From 3127692d297c0dd8f4a6d8673627db41046b86ff Mon Sep 17 00:00:00 2001
From: donpat1to <patrick@inca-vikingo.de>
Date: Tue, 21 Oct 2025 00:51:23 +0200
Subject: [PATCH] updated every file for database changes; starting scheduling
 debugging

---
 backend/src/controllers/authController.ts     |  49 +-
 backend/src/controllers/employeeController.ts | 246 +++++--
 backend/src/controllers/setupController.ts    |  13 +-
 backend/src/database/schema.sql               |  56 +-
 backend/src/middleware/auth.ts                |   3 +-
 backend/src/models/Employee.ts                |  24 +-
 .../src/models/defaults/employeeDefaults.ts   |  79 +-
 backend/src/models/helpers/employeeHelpers.ts |  82 ++-
 backend/src/models/scheduling.ts              |  11 +-
 backend/src/routes/employees.ts               |   6 +-
 backend/src/scripts/applyMigration.ts         | 198 +++--
 backend/src/scripts/initializeDatabase.ts     |  22 +-
 backend/src/services/SchedulingService.ts     |  13 +-
 backend/src/workers/scheduler-worker.ts       | 210 +++++-
 frontend/src/components/Scheduler.tsx         | 141 ----
 frontend/src/contexts/AuthContext.tsx         |   2 +-
 frontend/src/models/Employee.ts               |  26 +-
 .../src/models/defaults/employeeDefaults.ts   |  79 +-
 .../src/models/helpers/employeeHelpers.ts     |  83 ++-
 frontend/src/models/scheduling.ts             |  11 +-
 frontend/src/pages/Auth/Login.tsx             |   5 +-
 frontend/src/pages/Dashboard/Dashboard.tsx    |  20 +-
 .../components/AvailabilityManager.tsx        | 471 +++++++++---
 .../Employees/components/EmployeeForm.tsx     | 123 +++-
 .../Employees/components/EmployeeList.tsx     |  46 +-
 .../src/pages/ShiftPlans/ShiftPlanView.tsx    | 692 +++++++++++-------
 frontend/src/services/employeeService.ts      |  16 +
 27 files changed, 1861 insertions(+), 866 deletions(-)
 delete mode 100644 frontend/src/components/Scheduler.tsx

diff --git a/backend/src/controllers/authController.ts b/backend/src/controllers/authController.ts
index ebe8458..273cd90 100644
--- a/backend/src/controllers/authController.ts
+++ b/backend/src/controllers/authController.ts
@@ -39,7 +39,6 @@ export interface RegisterRequest {
 }
 
 function generateEmail(firstname: string, lastname: string): string {
-  // Convert German umlauts to their expanded forms
   const convertUmlauts = (str: string): string => {
     return str
       .toLowerCase()
@@ -49,7 +48,6 @@ function generateEmail(firstname: string, lastname: string): string {
       .replace(/ß/g, 'ss');
   };
 
-  // Remove any remaining special characters and convert to lowercase
   const cleanFirstname = convertUmlauts(firstname).replace(/[^a-z0-9]/g, '');
   const cleanLastname = convertUmlauts(lastname).replace(/[^a-z0-9]/g, '');
   return `${cleanFirstname}.${cleanLastname}@sp.de`;
@@ -70,8 +68,8 @@ export const login = async (req: Request, res: Response) => {
     const user = await db.get<any>(
       `SELECT 
         e.id, e.email, e.password, e.firstname, e.lastname, 
-        e.employee_type as employeeType, e.contract_type as contractType, 
-        e.can_work_alone as canWorkAlone, e.is_active as isActive,
+        e.employee_type, e.contract_type, 
+        e.can_work_alone, e.is_active, e.is_trainee,
         er.role
        FROM employees e
        LEFT JOIN employee_roles er ON e.id = er.employee_id
@@ -87,6 +85,15 @@ export const login = async (req: Request, res: Response) => {
       return res.status(401).json({ error: 'Ungültige Anmeldedaten' });
     }
 
+    // Update last_login with current timestamp
+    const currentTimestamp = new Date().toISOString();
+    await db.run(
+      'UPDATE employees SET last_login = ? WHERE id = ?', 
+      [currentTimestamp, user.id]
+    );
+
+    console.log('✅ Timestamp set:', currentTimestamp);
+
     // Verify password
     const validPassword = await bcrypt.compare(password, user.password);
     console.log('🔑 Password valid:', validPassword);
@@ -116,7 +123,12 @@ export const login = async (req: Request, res: Response) => {
     const { password: _, ...userWithoutPassword } = user;
     const userResponse = {
       ...userWithoutPassword,
-      roles: user.role ? [user.role] : ['user'] // Convert single role to array for frontend compatibility
+      employeeType: user.employee_type,
+      contractType: user.contract_type,
+      canWorkAlone: user.can_work_alone === 1,
+      isActive: user.is_active === 1,
+      isTrainee: user.is_trainee === 1,
+      roles: user.role ? [user.role] : ['user']
     };
 
     console.log('✅ Login successful for:', user.email);
@@ -147,8 +159,8 @@ export const getCurrentUser = async (req: Request, res: Response) => {
     const user = await db.get<any>(
       `SELECT 
         e.id, e.email, e.firstname, e.lastname,
-        e.employee_type as employeeType, e.contract_type as contractType, 
-        e.can_work_alone as canWorkAlone, e.is_active as isActive,
+        e.employee_type, e.contract_type, 
+        e.can_work_alone, e.is_active, e.is_trainee,
         er.role
        FROM employees e
        LEFT JOIN employee_roles er ON e.id = er.employee_id
@@ -167,6 +179,11 @@ export const getCurrentUser = async (req: Request, res: Response) => {
     // Format user response with roles array
     const userResponse = {
       ...user,
+      employeeType: user.employee_type,
+      contractType: user.contract_type,
+      canWorkAlone: user.can_work_alone === 1,
+      isActive: user.is_active === 1,
+      isTrainee: user.is_trainee === 1,
       roles: user.role ? [user.role] : ['user']
     };
 
@@ -237,18 +254,18 @@ export const register = async (req: Request, res: Response) => {
     await db.run('BEGIN TRANSACTION');
 
     try {
-      // Insert user without role (role is now in employee_roles table)
+      // ✅ CORRECTED: Use valid 'personell' type with proper contract type
       const result = await db.run(
-        `INSERT INTO employees (id, email, password, firstname, lastname, employee_type, contract_type, can_work_alone, is_active) 
-        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
-        [employeeId, email, hashedPassword, firstname, lastname, 'experienced', 'small', false, 1]
+        `INSERT INTO employees (id, email, password, firstname, lastname, employee_type, contract_type, can_work_alone, is_active, is_trainee) 
+        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+        [employeeId, email, hashedPassword, firstname, lastname, 'personell', 'small', false, 1, false]
       );
 
       if (!result.lastID) {
         throw new Error('Benutzer konnte nicht erstellt werden');
       }
 
-      // UPDATED: Insert roles into employee_roles table
+      // Insert roles into employee_roles table
       for (const role of roles) {
         await db.run(
           `INSERT INTO employee_roles (employee_id, role) VALUES (?, ?)`,
@@ -262,6 +279,7 @@ export const register = async (req: Request, res: Response) => {
       const newUser = await db.get<any>(
         `SELECT 
           e.id, e.email, e.firstname, e.lastname,
+          e.employee_type, e.contract_type, e.can_work_alone, e.is_active, e.is_trainee,
           er.role
          FROM employees e
          LEFT JOIN employee_roles er ON e.id = er.employee_id
@@ -273,6 +291,11 @@ export const register = async (req: Request, res: Response) => {
       // Format response with roles array
       const userResponse = {
         ...newUser,
+        employeeType: newUser.employee_type,
+        contractType: newUser.contract_type,
+        canWorkAlone: newUser.can_work_alone === 1,
+        isActive: newUser.is_active === 1,
+        isTrainee: newUser.is_trainee === 1,
         roles: newUser.role ? [newUser.role] : ['user']
       };
 
@@ -293,8 +316,6 @@ export const register = async (req: Request, res: Response) => {
 
 export const logout = async (req: Request, res: Response) => {
   try {
-    // Note: Since we're using JWTs, we don't need to do anything server-side
-    // The client should remove the token from storage
     res.json({ message: 'Erfolgreich abgemeldet' });
   } catch (error) {
     console.error('Logout error:', error);
diff --git a/backend/src/controllers/employeeController.ts b/backend/src/controllers/employeeController.ts
index 3cedbcd..aa3e056 100644
--- a/backend/src/controllers/employeeController.ts
+++ b/backend/src/controllers/employeeController.ts
@@ -7,7 +7,6 @@ import { AuthRequest } from '../middleware/auth.js';
 import { CreateEmployeeRequest } from '../models/Employee.js';
 
 function generateEmail(firstname: string, lastname: string): string {
-  // Convert German umlauts to their expanded forms
   const convertUmlauts = (str: string): string => {
     return str
       .toLowerCase()
@@ -17,7 +16,6 @@ function generateEmail(firstname: string, lastname: string): string {
       .replace(/ß/g, 'ss');
   };
 
-  // Remove any remaining special characters and convert to lowercase
   const cleanFirstname = convertUmlauts(firstname).replace(/[^a-z0-9]/g, '');
   const cleanLastname = convertUmlauts(lastname).replace(/[^a-z0-9]/g, '');
   
@@ -34,12 +32,13 @@ export const getEmployees = async (req: AuthRequest, res: Response): Promise<voi
     let query = `
       SELECT 
         e.id, e.email, e.firstname, e.lastname, 
-        e.is_active as isActive, 
-        e.employee_type as employeeType, 
-        e.contract_type as contractType,
-        e.can_work_alone as canWorkAlone,
-        e.created_at as createdAt, 
-        e.last_login as lastLogin,
+        e.is_active, 
+        e.employee_type, 
+        e.contract_type,
+        e.can_work_alone,
+        e.is_trainee,
+        e.created_at, 
+        e.last_login,
         er.role
       FROM employees e
       LEFT JOIN employee_roles er ON e.id = er.employee_id
@@ -49,14 +48,23 @@ export const getEmployees = async (req: AuthRequest, res: Response): Promise<voi
       query += ' WHERE e.is_active = 1';
     }
     
-    // UPDATED: Order by firstname and lastname
     query += ' ORDER BY e.firstname, e.lastname';
     
     const employees = await db.all<any>(query);
 
-    // Format employees with roles array for frontend compatibility
+    // Format employees with proper field names and roles array
     const employeesWithRoles = employees.map(emp => ({
-      ...emp,
+      id: emp.id,
+      email: emp.email,
+      firstname: emp.firstname,
+      lastname: emp.lastname,
+      isActive: emp.is_active === 1,
+      employeeType: emp.employee_type,
+      contractType: emp.contract_type,
+      canWorkAlone: emp.can_work_alone === 1,
+      isTrainee: emp.is_trainee === 1,
+      createdAt: emp.created_at,
+      lastLogin: emp.last_login,
       roles: emp.role ? [emp.role] : ['user']
     }));
 
@@ -72,16 +80,16 @@ export const getEmployee = async (req: AuthRequest, res: Response): Promise<void
   try {
     const { id } = req.params;
 
-    // UPDATED: Query with role from employee_roles table
     const employee = await db.get<any>(`
       SELECT 
         e.id, e.email, e.firstname, e.lastname, 
-        e.is_active as isActive, 
-        e.employee_type as employeeType, 
-        e.contract_type as contractType,
-        e.can_work_alone as canWorkAlone,
-        e.created_at as createdAt, 
-        e.last_login as lastLogin,
+        e.is_active, 
+        e.employee_type, 
+        e.contract_type,
+        e.can_work_alone,
+        e.is_trainee,
+        e.created_at, 
+        e.last_login,
         er.role
       FROM employees e
       LEFT JOIN employee_roles er ON e.id = er.employee_id
@@ -94,9 +102,19 @@ export const getEmployee = async (req: AuthRequest, res: Response): Promise<void
       return;
     }
 
-    // Format employee with roles array
+    // Format employee with proper field names
     const employeeWithRoles = {
-      ...employee,
+      id: employee.id,
+      email: employee.email,
+      firstname: employee.firstname,
+      lastname: employee.lastname,
+      isActive: employee.is_active === 1,
+      employeeType: employee.employee_type,
+      contractType: employee.contract_type,
+      canWorkAlone: employee.can_work_alone === 1,
+      isTrainee: employee.is_trainee === 1,
+      createdAt: employee.created_at,
+      lastLogin: employee.last_login,
       roles: employee.role ? [employee.role] : ['user']
     };
 
@@ -118,17 +136,64 @@ export const createEmployee = async (req: AuthRequest, res: Response): Promise<v
       password, 
       firstname, 
       lastname, 
-      roles = ['user'], // UPDATED: Now uses roles array
+      roles = ['user'],
       employeeType, 
       contractType,
-      canWorkAlone
+      canWorkAlone = false,
+      isTrainee = false
     } = req.body as CreateEmployeeRequest;
 
     // Validation
-    if (!password || !firstname || !lastname || !employeeType || !contractType) {
+    if (!password || !firstname || !lastname || !employeeType) {
       console.log('❌ Validation failed: Missing required fields');
       res.status(400).json({ 
-        error: 'Password, firstname, lastname, employeeType und contractType sind erforderlich' 
+        error: 'Password, firstname, lastname und employeeType sind erforderlich' 
+      });
+      return;
+    }
+
+    // ✅ ENHANCED: Validate employee type exists and get category info
+    const employeeTypeInfo = await db.get<{type: string, category: string, has_contract_type: number}>(
+      'SELECT type, category, has_contract_type FROM employee_types WHERE type = ?',
+      [employeeType]
+    );
+
+    if (!employeeTypeInfo) {
+      res.status(400).json({ 
+        error: `Ungültiger employeeType: ${employeeType}. Gültige Typen: manager, personell, apprentice, guest` 
+      });
+      return;
+    }
+
+    // ✅ ENHANCED: Contract type validation based on category
+    if (employeeTypeInfo.has_contract_type === 1) {
+      // Internal types require contract type
+      if (!contractType) {
+        res.status(400).json({ 
+          error: `contractType ist erforderlich für employeeType: ${employeeType}` 
+        });
+        return;
+      }
+      if (!['small', 'large', 'flexible'].includes(contractType)) {
+        res.status(400).json({ 
+          error: `Ungültiger contractType: ${contractType}. Gültige Werte: small, large, flexible` 
+        });
+        return;
+      }
+    } else {
+      // External types (guest) should not have contract type
+      if (contractType) {
+        res.status(400).json({ 
+          error: `contractType ist nicht erlaubt für employeeType: ${employeeType}` 
+        });
+        return;
+      }
+    }
+
+    // ✅ ENHANCED: isTrainee validation - only applicable for personell type
+    if (isTrainee && employeeType !== 'personell') {
+      res.status(400).json({ 
+        error: `isTrainee ist nur für employeeType 'personell' erlaubt` 
       });
       return;
     }
@@ -156,12 +221,12 @@ export const createEmployee = async (req: AuthRequest, res: Response): Promise<v
     await db.run('BEGIN TRANSACTION');
 
     try {
-      // UPDATED: Insert employee without role (role is now in employee_roles table)
+      // Insert employee with proper contract type handling
       await db.run(
         `INSERT INTO employees (
           id, email, password, firstname, lastname, employee_type, contract_type, can_work_alone, 
-          is_active
-        ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+          is_active, is_trainee
+        ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
         [
           employeeId, 
           email, 
@@ -169,13 +234,14 @@ export const createEmployee = async (req: AuthRequest, res: Response): Promise<v
           firstname, 
           lastname, 
           employeeType, 
-          contractType,
+          contractType, // Will be NULL for external types
           canWorkAlone ? 1 : 0,
-          1
+          1,
+          isTrainee ? 1 : 0
         ]
       );
 
-      // UPDATED: Insert roles into employee_roles table
+      // Insert roles into employee_roles table
       for (const role of roles) {
         await db.run(
           `INSERT INTO employee_roles (employee_id, role) VALUES (?, ?)`,
@@ -185,16 +251,17 @@ export const createEmployee = async (req: AuthRequest, res: Response): Promise<v
 
       await db.run('COMMIT');
 
-      // Return created employee with role from employee_roles
+      // Return created employee
       const newEmployee = await db.get<any>(`
         SELECT 
           e.id, e.email, e.firstname, e.lastname, 
-          e.is_active as isActive,
-          e.employee_type as employeeType, 
-          e.contract_type as contractType,
-          e.can_work_alone as canWorkAlone,
-          e.created_at as createdAt, 
-          e.last_login as lastLogin,
+          e.is_active,
+          e.employee_type, 
+          e.contract_type,
+          e.can_work_alone,
+          e.is_trainee,
+          e.created_at, 
+          e.last_login,
           er.role
         FROM employees e
         LEFT JOIN employee_roles er ON e.id = er.employee_id
@@ -202,9 +269,19 @@ export const createEmployee = async (req: AuthRequest, res: Response): Promise<v
         LIMIT 1
       `, [employeeId]);
 
-      // Format response with roles array
+      // Format response with proper field names
       const employeeWithRoles = {
-        ...newEmployee,
+        id: newEmployee.id,
+        email: newEmployee.email,
+        firstname: newEmployee.firstname,
+        lastname: newEmployee.lastname,
+        isActive: newEmployee.is_active === 1,
+        employeeType: newEmployee.employee_type,
+        contractType: newEmployee.contract_type,
+        canWorkAlone: newEmployee.can_work_alone === 1,
+        isTrainee: newEmployee.is_trainee === 1,
+        createdAt: newEmployee.created_at,
+        lastLogin: newEmployee.last_login,
         roles: newEmployee.role ? [newEmployee.role] : ['user']
       };
 
@@ -223,9 +300,12 @@ export const createEmployee = async (req: AuthRequest, res: Response): Promise<v
 export const updateEmployee = async (req: AuthRequest, res: Response): Promise<void> => {
   try {
     const { id } = req.params;
-    const { firstname, lastname, roles, isActive, employeeType, contractType, canWorkAlone } = req.body;
+    const { firstname, lastname, roles, isActive, employeeType, contractType, canWorkAlone, isTrainee } = req.body;
 
-    console.log('📝 Update Employee Request:', { id, firstname, lastname, roles, isActive, employeeType, contractType, canWorkAlone });
+    console.log('📝 Update Employee Request:', { 
+      id, firstname, lastname, roles, isActive, 
+      employeeType, contractType, canWorkAlone, isTrainee 
+    });
 
     // Check if employee exists and get current data
     const existingEmployee = await db.get<any>('SELECT * FROM employees WHERE id = ?', [id]);
@@ -234,6 +314,21 @@ export const updateEmployee = async (req: AuthRequest, res: Response): Promise<v
       return;
     }
 
+    // Validate employee type if provided
+    if (employeeType) {
+      const validEmployeeType = await db.get(
+        'SELECT type FROM employee_types WHERE type = ?',
+        [employeeType]
+      );
+
+      if (!validEmployeeType) {
+        res.status(400).json({ 
+          error: `Ungültiger employeeType: ${employeeType}` 
+        });
+        return;
+      }
+    }
+
     // Generate new email if firstname or lastname changed
     let email = existingEmployee.email;
     if (firstname || lastname) {
@@ -259,7 +354,7 @@ export const updateEmployee = async (req: AuthRequest, res: Response): Promise<v
     await db.run('BEGIN TRANSACTION');
 
     try {
-      // UPDATED: Update employee without role (role is now in employee_roles table)
+      // Update employee with new schema
       await db.run(
         `UPDATE employees 
          SET firstname = COALESCE(?, firstname),
@@ -268,12 +363,13 @@ export const updateEmployee = async (req: AuthRequest, res: Response): Promise<v
              is_active = COALESCE(?, is_active),
              employee_type = COALESCE(?, employee_type),
              contract_type = COALESCE(?, contract_type),
-             can_work_alone = COALESCE(?, can_work_alone)
+             can_work_alone = COALESCE(?, can_work_alone),
+             is_trainee = COALESCE(?, is_trainee)
          WHERE id = ?`,
-        [firstname, lastname, email, isActive, employeeType, contractType, canWorkAlone, id]
+        [firstname, lastname, email, isActive, employeeType, contractType, canWorkAlone, isTrainee, id]
       );
 
-      // UPDATED: Update roles if provided
+      // Update roles if provided
       if (roles) {
         // Delete existing roles
         await db.run('DELETE FROM employee_roles WHERE employee_id = ?', [id]);
@@ -291,16 +387,17 @@ export const updateEmployee = async (req: AuthRequest, res: Response): Promise<v
 
       console.log('✅ Employee updated successfully with email:', email);
 
-      // Return updated employee with role from employee_roles
+      // Return updated employee
       const updatedEmployee = await db.get<any>(`
         SELECT 
           e.id, e.email, e.firstname, e.lastname, 
-          e.is_active as isActive, 
-          e.employee_type as employeeType, 
-          e.contract_type as contractType,
-          e.can_work_alone as canWorkAlone,
-          e.created_at as createdAt, 
-          e.last_login as lastLogin,
+          e.is_active, 
+          e.employee_type, 
+          e.contract_type,
+          e.can_work_alone,
+          e.is_trainee,
+          e.created_at, 
+          e.last_login,
           er.role
         FROM employees e
         LEFT JOIN employee_roles er ON e.id = er.employee_id
@@ -308,9 +405,19 @@ export const updateEmployee = async (req: AuthRequest, res: Response): Promise<v
         LIMIT 1
       `, [id]);
 
-      // Format response with roles array
+      // Format response with proper field names
       const employeeWithRoles = {
-        ...updatedEmployee,
+        id: updatedEmployee.id,
+        email: updatedEmployee.email,
+        firstname: updatedEmployee.firstname,
+        lastname: updatedEmployee.lastname,
+        isActive: updatedEmployee.is_active === 1,
+        employeeType: updatedEmployee.employee_type,
+        contractType: updatedEmployee.contract_type,
+        canWorkAlone: updatedEmployee.can_work_alone === 1,
+        isTrainee: updatedEmployee.is_trainee === 1,
+        createdAt: updatedEmployee.created_at,
+        lastLogin: updatedEmployee.last_login,
         roles: updatedEmployee.role ? [updatedEmployee.role] : ['user']
       };
 
@@ -434,6 +541,7 @@ export const getAvailabilities = async (req: AuthRequest, res: Response): Promis
       id: avail.id,
       employeeId: avail.employee_id,
       planId: avail.plan_id,
+      shiftId: avail.shift_id,
       dayOfWeek: avail.day_of_week,
       timeSlotId: avail.time_slot_id,
       preferenceLevel: avail.preference_level,
@@ -561,4 +669,34 @@ export const changePassword = async (req: AuthRequest, res: Response): Promise<v
     console.error('Error changing password:', error);
     res.status(500).json({ error: 'Internal server error' });
   }
+};
+
+export const updateLastLogin = async (req: AuthRequest, res: Response): Promise<void> => {
+  try {
+    const { id } = req.params;
+
+    // Check if employee exists
+    const employee = await db.get('SELECT id FROM employees WHERE id = ?', [id]);
+    if (!employee) {
+      res.status(404).json({ error: 'Employee not found' });
+      return;
+    }
+
+    // Update last_login with current timestamp
+    const currentTimestamp = new Date().toISOString();
+    await db.run(
+      'UPDATE employees SET last_login = ? WHERE id = ?', 
+      [currentTimestamp, id]
+    );
+
+    console.log(`✅ Last login updated for employee ${id}: ${currentTimestamp}`);
+    
+    res.json({ 
+      message: 'Last login updated successfully',
+      lastLogin: currentTimestamp
+    });
+  } catch (error) {
+    console.error('Error updating last login:', error);
+    res.status(500).json({ error: 'Internal server error' });
+  }
 };
\ No newline at end of file
diff --git a/backend/src/controllers/setupController.ts b/backend/src/controllers/setupController.ts
index a1c773e..b2a9672 100644
--- a/backend/src/controllers/setupController.ts
+++ b/backend/src/controllers/setupController.ts
@@ -5,9 +5,7 @@ import { v4 as uuidv4 } from 'uuid';
 import { randomUUID } from 'crypto';
 import { db } from '../services/databaseService.js';
 
-// Add the same email generation function
 function generateEmail(firstname: string, lastname: string): string {
-  // Convert German umlauts to their expanded forms
   const convertUmlauts = (str: string): string => {
     return str
       .toLowerCase()
@@ -17,7 +15,6 @@ function generateEmail(firstname: string, lastname: string): string {
       .replace(/ß/g, 'ss');
   };
 
-  // Remove any remaining special characters and convert to lowercase
   const cleanFirstname = convertUmlauts(firstname).replace(/[^a-z0-9]/g, '');
   const cleanLastname = convertUmlauts(lastname).replace(/[^a-z0-9]/g, '');
   
@@ -98,14 +95,14 @@ export const setupAdmin = async (req: Request, res: Response): Promise<void> =>
     await db.run('BEGIN TRANSACTION');
 
     try {
-      // Create admin user in employees table
+      // ✅ CORRECTED: Create admin with valid 'manager' type and 'flexible' contract
       await db.run(
-        `INSERT INTO employees (id, email, password, firstname, lastname, employee_type, contract_type, can_work_alone, is_active)
-        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
-        [adminId, email, hashedPassword, firstname, lastname, 'manager', 'large', true, 1]
+        `INSERT INTO employees (id, email, password, firstname, lastname, employee_type, contract_type, can_work_alone, is_active, is_trainee)
+        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+        [adminId, email, hashedPassword, firstname, lastname, 'manager', 'flexible', true, 1, false]
       );
 
-      // UPDATED: Assign admin role in employee_roles table
+      // Assign admin role in employee_roles table
       await db.run(
         `INSERT INTO employee_roles (employee_id, role) VALUES (?, ?)`,
         [adminId, 'admin']
diff --git a/backend/src/database/schema.sql b/backend/src/database/schema.sql
index 39f0849..452036e 100644
--- a/backend/src/database/schema.sql
+++ b/backend/src/database/schema.sql
@@ -1,3 +1,28 @@
+-- Employee Types
+CREATE TABLE IF NOT EXISTS employee_types (
+  type TEXT PRIMARY KEY,
+  category TEXT CHECK(category IN ('internal', 'external')) NOT NULL,
+  has_contract_type BOOLEAN NOT NULL DEFAULT FALSE
+);
+
+-- Default Employee Types
+-- 'manager' and 'apprentice' contract_type_default = flexible
+-- 'personell' contract_type_default = small
+-- employee_types category 'external' contract_type = NONE
+-- moved experienced and trainee into personell -> is_trainee boolean added in employees
+INSERT OR IGNORE INTO employee_types (type, category, has_contract_type) VALUES 
+  ('manager', 'internal', 1),
+  ('personell', 'internal', 1),
+  ('apprentice', 'internal', 1),
+  ('guest', 'external', 0);
+
+-- Roles lookup table
+CREATE TABLE IF NOT EXISTS roles (
+  role TEXT PRIMARY KEY CHECK(role IN ('admin', 'user', 'maintenance')),
+  authority_level INTEGER NOT NULL UNIQUE CHECK(authority_level BETWEEN 1 AND 100),
+  description TEXT
+);
+
 -- Employees table
 CREATE TABLE IF NOT EXISTS employees (
   id TEXT PRIMARY KEY,
@@ -5,30 +30,27 @@ CREATE TABLE IF NOT EXISTS employees (
   password TEXT NOT NULL,
   firstname TEXT NOT NULL,
   lastname TEXT NOT NULL,
-  employee_type TEXT CHECK(employee_type IN ('manager', 'trainee', 'experienced')) NOT NULL,
-  contract_type TEXT CHECK(contract_type IN ('small', 'large')) NOT NULL,
+  employee_type TEXT NOT NULL REFERENCES employee_types(type),
+  contract_type TEXT CHECK(contract_type IN ('small', 'large', 'flexible')),
   can_work_alone BOOLEAN DEFAULT FALSE,
+  is_trainee BOOLEAN DEFAULT FALSE NOT NULL,
   is_active BOOLEAN DEFAULT TRUE,
   created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
   last_login TEXT DEFAULT NULL
 );
 
--- Roles lookup table
-CREATE TABLE IF NOT EXISTS roles (
-  role TEXT PRIMARY KEY CHECK(role IN ('admin', 'user', 'maintenance'))
-);
-
--- Junction table: many-to-many relationship
+-- Roles Employee Junction table (NACH employees und roles)
 CREATE TABLE IF NOT EXISTS employee_roles (
   employee_id TEXT NOT NULL REFERENCES employees(id) ON DELETE CASCADE,
   role TEXT NOT NULL REFERENCES roles(role),
   PRIMARY KEY (employee_id, role)
 );
 
--- Insert default roles if they don't exist
-INSERT OR IGNORE INTO roles (role) VALUES ('admin');
-INSERT OR IGNORE INTO roles (role) VALUES ('user');
-INSERT OR IGNORE INTO roles (role) VALUES ('maintenance');
+-- Insert default roles (NACH roles Tabelle)
+INSERT OR IGNORE INTO roles (role, authority_level, description) VALUES 
+  ('admin', 100, 'Vollzugriff'),
+  ('maintenance', 50, 'Wartungszugriff'),
+  ('user', 10, 'Standardbenutzer');
 
 -- Shift plans table
 CREATE TABLE IF NOT EXISTS shift_plans (
@@ -109,29 +131,21 @@ CREATE TABLE IF NOT EXISTS employee_availability (
   UNIQUE(employee_id, plan_id, shift_id)
 );
 
--- Performance indexes (UPDATED - removed role index from employees)
+-- Performance indexes
 CREATE INDEX IF NOT EXISTS idx_employees_email_active ON employees(email, is_active);
 CREATE INDEX IF NOT EXISTS idx_employees_type_active ON employees(employee_type, is_active);
-
--- Index for employee_roles table (NEW)
 CREATE INDEX IF NOT EXISTS idx_employee_roles_employee ON employee_roles(employee_id);
 CREATE INDEX IF NOT EXISTS idx_employee_roles_role ON employee_roles(role);
-
 CREATE INDEX IF NOT EXISTS idx_shift_plans_status_date ON shift_plans(status, start_date, end_date);
 CREATE INDEX IF NOT EXISTS idx_shift_plans_created_by ON shift_plans(created_by);
 CREATE INDEX IF NOT EXISTS idx_shift_plans_template ON shift_plans(is_template, status);
-
 CREATE INDEX IF NOT EXISTS idx_time_slots_plan ON time_slots(plan_id);
-
 CREATE INDEX IF NOT EXISTS idx_shifts_plan_day ON shifts(plan_id, day_of_week);
 CREATE INDEX IF NOT EXISTS idx_shifts_required_employees ON shifts(required_employees);
 CREATE INDEX IF NOT EXISTS idx_shifts_plan_time ON shifts(plan_id, time_slot_id, day_of_week);
-
 CREATE INDEX IF NOT EXISTS idx_scheduled_shifts_plan_date ON scheduled_shifts(plan_id, date);
 CREATE INDEX IF NOT EXISTS idx_scheduled_shifts_date_time ON scheduled_shifts(date, time_slot_id);
 CREATE INDEX IF NOT EXISTS idx_scheduled_shifts_required_employees ON scheduled_shifts(required_employees);
-
 CREATE INDEX IF NOT EXISTS idx_shift_assignments_employee ON shift_assignments(employee_id);
 CREATE INDEX IF NOT EXISTS idx_shift_assignments_shift ON shift_assignments(scheduled_shift_id);
-
 CREATE INDEX IF NOT EXISTS idx_employee_availability_employee_plan ON employee_availability(employee_id, plan_id);
\ No newline at end of file
diff --git a/backend/src/middleware/auth.ts b/backend/src/middleware/auth.ts
index 9b81a89..36320f5 100644
--- a/backend/src/middleware/auth.ts
+++ b/backend/src/middleware/auth.ts
@@ -44,10 +44,11 @@ export const authMiddleware = (req: AuthRequest, res: Response, next: NextFuncti
 export const requireRole = (roles: string[]) => {
   return (req: AuthRequest, res: Response, next: NextFunction): void => {
     if (!req.user || !roles.includes(req.user.role)) {
-      console.log('❌ Insufficient permissions for user:', req.user?.email);
+      console.log(`❌ Insufficient permissions for user: ${req.user?.email}, role: ${req.user?.role}, required: ${roles.join(', ')}`);
       res.status(403).json({ error: 'Access denied. Insufficient permissions.' });
       return;
     }
+    console.log(`✅ Role check passed for user: ${req.user.email}, role: ${req.user.role}`);
     next();
   };
 };
\ No newline at end of file
diff --git a/backend/src/models/Employee.ts b/backend/src/models/Employee.ts
index 0114021..6cfcb29 100644
--- a/backend/src/models/Employee.ts
+++ b/backend/src/models/Employee.ts
@@ -4,10 +4,11 @@ export interface Employee {
   email: string;
   firstname: string;
   lastname: string;
-  employeeType: 'manager' | 'trainee' | 'experienced';
-  contractType: 'small' | 'large';
+  employeeType: 'manager' | 'personell' | 'apprentice' | 'guest';
+  contractType?: 'small' | 'large' | 'flexible';
   canWorkAlone: boolean;
   isActive: boolean;
+  isTrainee: boolean;
   createdAt: string;
   lastLogin?: string | null;
   roles?: string[];
@@ -18,19 +19,21 @@ export interface CreateEmployeeRequest {
   firstname: string;
   lastname: string;
   roles?: string[];
-  employeeType: 'manager' | 'trainee' | 'experienced';
-  contractType: 'small' | 'large';
+  employeeType: 'manager' | 'personell' | 'apprentice' | 'guest';
+  contractType?: 'small' | 'large' | 'flexible';
   canWorkAlone: boolean;
+  isTrainee?: boolean;
 }
 
 export interface UpdateEmployeeRequest {
   firstname?: string;
   lastname?: string;
   roles?: string[];
-  employeeType?: 'manager' | 'trainee' | 'experienced';
-  contractType?: 'small' | 'large';
+  employeeType?: 'manager' | 'personell' | 'apprentice' | 'guest';
+  contractType?: 'small' | 'large' | 'flexible';
   canWorkAlone?: boolean;
   isActive?: boolean;
+  isTrainee?: boolean;
 }
 
 export interface EmployeeWithPassword extends Employee {
@@ -41,7 +44,7 @@ export interface EmployeeAvailability {
   id: string;
   employeeId: string;
   planId: string;
-  shiftId: string; // Now references shift_id instead of time_slot_id + day_of_week
+  shiftId: string;
   preferenceLevel: 1 | 2 | 3; // 1:preferred, 2:available, 3:unavailable
   notes?: string;
 }
@@ -83,4 +86,11 @@ export interface Role {
 export interface EmployeeRole {
   employeeId: string;
   role: 'admin' | 'user' | 'maintenance';
+}
+
+// Employee type configuration
+export interface EmployeeType {
+  type: 'manager' | 'personell' | 'apprentice' | 'guest';
+  category: 'internal' | 'external';
+  has_contract_type: boolean;
 }
\ No newline at end of file
diff --git a/backend/src/models/defaults/employeeDefaults.ts b/backend/src/models/defaults/employeeDefaults.ts
index 7a61cae..e80e189 100644
--- a/backend/src/models/defaults/employeeDefaults.ts
+++ b/backend/src/models/defaults/employeeDefaults.ts
@@ -4,19 +4,41 @@ import { EmployeeAvailability, ManagerAvailability } from '../Employee.js';
 // Default employee data for quick creation
 export const EMPLOYEE_DEFAULTS = {
   role: 'user' as const,
-  employeeType: 'experienced' as const,
+  employeeType: 'personell' as const,
   contractType: 'small' as const,
   canWorkAlone: false,
-  isActive: true
+  isActive: true,
+  isTrainee: false
 };
 
 // Manager-specific defaults
 export const MANAGER_DEFAULTS = {
   role: 'admin' as const,
   employeeType: 'manager' as const,
-  contractType: 'large' as const,
+  contractType: 'flexible' as const,
   canWorkAlone: true,
-  isActive: true
+  isActive: true,
+  isTrainee: false
+};
+
+// Apprentice defaults
+export const APPRENTICE_DEFAULTS = {
+  role: 'user' as const,
+  employeeType: 'apprentice' as const,
+  contractType: 'flexible' as const,
+  canWorkAlone: false,
+  isActive: true,
+  isTrainee: false
+};
+
+// Guest defaults
+export const GUEST_DEFAULTS = {
+  role: 'user' as const,
+  employeeType: 'guest' as const,
+  contractType: undefined,
+  canWorkAlone: false,
+  isActive: true,
+  isTrainee: false
 };
 
 export const EMPLOYEE_TYPE_CONFIG = {
@@ -24,22 +46,37 @@ export const EMPLOYEE_TYPE_CONFIG = {
     value: 'manager' as const,
     label: 'Chef/Administrator', 
     color: '#e74c3c',
+    category: 'internal' as const,
+    hasContractType: true,
     independent: true,
     description: 'Vollzugriff auf alle Funktionen und Mitarbeiterverwaltung'
   },
-  experienced: { 
-    value: 'experienced' as const,
-    label: 'Erfahren', 
+  personell: { 
+    value: 'personell' as const,
+    label: 'Personal', 
     color: '#3498db',
+    category: 'internal' as const,
+    hasContractType: true,
     independent: true,
-    description: 'Langjährige Erfahrung, kann komplexe Aufgaben übernehmen'
+    description: 'Reguläre Mitarbeiter mit Vertrag'
   },
-  trainee: { 
-    value: 'trainee' as const,
-    label: 'Neuling', 
-    color: '#27ae60', 
+  apprentice: { 
+    value: 'apprentice' as const,
+    label: 'Auszubildender', 
+    color: '#9b59b6',
+    category: 'internal' as const,
+    hasContractType: true,
     independent: false,
-    description: 'Benötigt Einarbeitung und Unterstützung'
+    description: 'Auszubildende mit flexiblem Vertrag'
+  },
+  guest: { 
+    value: 'guest' as const,
+    label: 'Gast', 
+    color: '#95a5a6',
+    category: 'external' as const,
+    hasContractType: false,
+    independent: false,
+    description: 'Externe Mitarbeiter ohne Vertrag'
   }
 } as const;
 
@@ -53,9 +90,10 @@ export const ROLE_CONFIG = [
 export const CONTRACT_TYPE_DESCRIPTIONS = {
   small: '1 Schicht pro Woche',
   large: '2 Schichten pro Woche',
-  manager: 'Kein Vertragslimit - Immer MO und DI verfügbar'
+  flexible: 'Flexible Arbeitszeiten'
 } as const;
 
+
 // Availability preference descriptions
 export const AVAILABILITY_PREFERENCES = {
   1: { label: 'Bevorzugt', color: '#10b981', description: 'Möchte diese Schicht arbeiten' },
@@ -104,4 +142,17 @@ export function createManagerDefaultSchedule(managerId: string, planId: string,
   }
   
   return assignments;
+}
+
+export function getDefaultsByEmployeeType(employeeType: string) {
+  switch (employeeType) {
+    case 'manager':
+      return MANAGER_DEFAULTS;
+    case 'apprentice':
+      return APPRENTICE_DEFAULTS;
+    case 'guest':
+      return GUEST_DEFAULTS;
+    default:
+      return EMPLOYEE_DEFAULTS;
+  }
 }
\ No newline at end of file
diff --git a/backend/src/models/helpers/employeeHelpers.ts b/backend/src/models/helpers/employeeHelpers.ts
index 9c75ecf..63b4f45 100644
--- a/backend/src/models/helpers/employeeHelpers.ts
+++ b/backend/src/models/helpers/employeeHelpers.ts
@@ -1,9 +1,8 @@
 // backend/src/models/helpers/employeeHelpers.ts
 import { Employee, CreateEmployeeRequest, EmployeeAvailability } from '../Employee.js';
 
-// Email generation function (same as in controllers)
+// Email generation function
 function generateEmail(firstname: string, lastname: string): string {
-  // Convert German umlauts to their expanded forms
   const convertUmlauts = (str: string): string => {
     return str
       .toLowerCase()
@@ -13,19 +12,16 @@ function generateEmail(firstname: string, lastname: string): string {
       .replace(/ß/g, 'ss');
   };
 
-  // Remove any remaining special characters and convert to lowercase
   const cleanFirstname = convertUmlauts(firstname).replace(/[^a-z0-9]/g, '');
   const cleanLastname = convertUmlauts(lastname).replace(/[^a-z0-9]/g, '');
   
   return `${cleanFirstname}.${cleanLastname}@sp.de`;
 }
 
-// UPDATED: Validation for new employee model
+// UPDATED: Validation for new employee model with employee types
 export function validateEmployeeData(employee: CreateEmployeeRequest): string[] {
   const errors: string[] = [];
 
-  // Email is now auto-generated, so no email validation needed
-  
   if (employee.password?.length < 6) {
     errors.push('Password must be at least 6 characters long');
   }
@@ -38,24 +34,70 @@ export function validateEmployeeData(employee: CreateEmployeeRequest): string[]
     errors.push('Last name is required and must be at least 2 characters long');
   }
 
+  // Validate employee type
+  const validEmployeeTypes = ['manager', 'personell', 'apprentice', 'guest'];
+  if (!employee.employeeType || !validEmployeeTypes.includes(employee.employeeType)) {
+    errors.push(`Employee type must be one of: ${validEmployeeTypes.join(', ')}`);
+  }
+
+  // Validate contract type based on employee type
+  if (employee.employeeType !== 'guest') {
+    // Internal types require contract type
+    if (!employee.contractType) {
+      errors.push(`Contract type is required for employee type: ${employee.employeeType}`);
+    } else {
+      const validContractTypes = ['small', 'large', 'flexible'];
+      if (!validContractTypes.includes(employee.contractType)) {
+        errors.push(`Contract type must be one of: ${validContractTypes.join(', ')}`);
+      }
+    }
+  } else {
+    // External types (guest) should not have contract type
+    if (employee.contractType) {
+      errors.push('Contract type is not allowed for guest employees');
+    }
+  }
+
+  // Validate isTrainee - only applicable for personell type
+  if (employee.isTrainee && employee.employeeType !== 'personell') {
+    errors.push('isTrainee is only allowed for personell employee type');
+  }
+
   return errors;
 }
 
-// Generate email for employee (new helper function)
+// Generate email for employee
 export function generateEmployeeEmail(firstname: string, lastname: string): string {
   return generateEmail(firstname, lastname);
 }
 
-// Simplified business logic helpers
+// UPDATED: Business logic helpers for new employee types
 export const isManager = (employee: Employee): boolean => 
   employee.employeeType === 'manager';
 
+export const isPersonell = (employee: Employee): boolean => 
+  employee.employeeType === 'personell';
+
+export const isApprentice = (employee: Employee): boolean => 
+  employee.employeeType === 'apprentice';
+
+export const isGuest = (employee: Employee): boolean => 
+  employee.employeeType === 'guest';
+
+export const isInternal = (employee: Employee): boolean =>
+  ['manager', 'personell', 'apprentice'].includes(employee.employeeType);
+
+export const isExternal = (employee: Employee): boolean =>
+  employee.employeeType === 'guest';
+
+// UPDATED: Trainee logic - now based on isTrainee field for personell type
 export const isTrainee = (employee: Employee): boolean => 
-  employee.employeeType === 'trainee';
+  employee.employeeType === 'personell' && employee.isTrainee;
 
 export const isExperienced = (employee: Employee): boolean => 
-  employee.employeeType === 'experienced';
+  employee.employeeType === 'personell' && !employee.isTrainee;
 
+// Role-based helpers
 export const isAdmin = (employee: Employee): boolean => 
   employee.roles?.includes('admin') || false;
 
@@ -65,13 +107,11 @@ export const isMaintenance = (employee: Employee): boolean =>
 export const isUser = (employee: Employee): boolean => 
   employee.roles?.includes('user') || false;
 
+// UPDATED: Work alone permission - managers and experienced personell can work alone
 export const canEmployeeWorkAlone = (employee: Employee): boolean => 
-  employee.canWorkAlone && isExperienced(employee);
+  employee.canWorkAlone && (isManager(employee) || isExperienced(employee));
 
-export const getEmployeeWorkHours = (employee: Employee): number =>
-  isManager(employee) ? 999 : (employee.contractType === 'small' ? 1 : 2);
-
-// New helper for full name display
+// Helper for full name display
 export const getFullName = (employee: { firstname: string; lastname: string }): string =>
   `${employee.firstname} ${employee.lastname}`;
 
@@ -92,4 +132,14 @@ export function validateAvailabilityData(availability: Omit<EmployeeAvailability
   }
 
   return errors;
-}
\ No newline at end of file
+}
+
+// UPDATED: Helper to get employee type category
+export const getEmployeeCategory = (employee: Employee): 'internal' | 'external' => {
+  return isInternal(employee) ? 'internal' : 'external';
+};
+
+// Helper to check if employee requires contract type
+export const requiresContractType = (employee: Employee): boolean => {
+  return isInternal(employee);
+};
\ No newline at end of file
diff --git a/backend/src/models/scheduling.ts b/backend/src/models/scheduling.ts
index 5943cc1..b8a9c14 100644
--- a/backend/src/models/scheduling.ts
+++ b/backend/src/models/scheduling.ts
@@ -7,10 +7,10 @@ export interface Availability {
   id: string;
   employeeId: string;
   planId: string;
-  shiftId: string; // Now references shift_id instead of time_slot_id + day_of_week
-  preferenceLevel: 1 | 2 | 3; // 1:preferred, 2:available, 3:unavailable
+  shiftId: string;
+  preferenceLevel: 1 | 2 | 3;
   notes?: string;
-  // Optional convenience fields (can be joined from shifts and time_slots tables)
+  // Optional convenience fields
   dayOfWeek?: number;
   timeSlotId?: string;
   timeSlotName?: string;
@@ -30,7 +30,7 @@ export interface Constraint {
     maxHoursPerWeek?: number;
     [key: string]: any;
   };
-  weight?: number; // For soft constraints
+  weight?: number;
 }
 
 export interface ScheduleRequest {
@@ -153,8 +153,9 @@ export interface AvailabilityWithDetails extends Availability {
     id: string;
     firstname: string;
     lastname: string;
-    employeeType: 'manager' | 'trainee' | 'experienced';
+    employeeType: 'manager' | 'personell' | 'apprentice' | 'guest';
     canWorkAlone: boolean;
+    isTrainee: boolean;
   };
   shift?: {
     dayOfWeek: number;
diff --git a/backend/src/routes/employees.ts b/backend/src/routes/employees.ts
index d458c47..c970b94 100644
--- a/backend/src/routes/employees.ts
+++ b/backend/src/routes/employees.ts
@@ -9,7 +9,8 @@ import {
   deleteEmployee,
   getAvailabilities,
   updateAvailabilities,
-  changePassword
+  changePassword,
+  updateLastLogin
 } from '../controllers/employeeController.js';
 
 const router = express.Router();
@@ -18,12 +19,13 @@ const router = express.Router();
 router.use(authMiddleware);
 
 // Employee CRUD Routes
-router.get('/', authMiddleware, getEmployees);
+router.get('/', requireRole(['admin']), getEmployees);
 router.get('/:id', requireRole(['admin', 'instandhalter']), getEmployee);
 router.post('/', requireRole(['admin']), createEmployee);
 router.put('/:id', requireRole(['admin']), updateEmployee);
 router.delete('/:id', requireRole(['admin']), deleteEmployee);
 router.put('/:id/password', authMiddleware, changePassword);
+router.put('/:id/last-login', authMiddleware, updateLastLogin);
 
 // Availability Routes
 router.get('/:employeeId/availabilities', authMiddleware, getAvailabilities);
diff --git a/backend/src/scripts/applyMigration.ts b/backend/src/scripts/applyMigration.ts
index 1efeacc..ef6832e 100644
--- a/backend/src/scripts/applyMigration.ts
+++ b/backend/src/scripts/applyMigration.ts
@@ -6,6 +6,25 @@ import { dirname, join } from 'path';
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = dirname(__filename);
 
+// Define interfaces for type safety
+interface TableColumnInfo {
+  cid: number;
+  name: string;
+  type: string;
+  notnull: number;
+  dflt_value: string | null;
+  pk: number;
+}
+
+interface CountResult {
+  count: number;
+}
+
+interface EmployeeRecord {
+  id: string;
+  // Note: roles column doesn't exist in new schema
+}
+
 // Helper function to ensure migrations are tracked
 async function ensureMigrationTable() {
   await db.exec(`
@@ -19,7 +38,7 @@ async function ensureMigrationTable() {
 
 // Helper function to check if a migration has been applied
 async function isMigrationApplied(migrationName: string): Promise<boolean> {
-  const result = await db.get<{ count: number }>(
+  const result = await db.get<CountResult>(
     'SELECT COUNT(*) as count FROM applied_migrations WHERE name = ?',
     [migrationName]
   );
@@ -34,6 +53,85 @@ async function markMigrationAsApplied(migrationName: string) {
   );
 }
 
+// UPDATED: Function to handle schema changes for the new employee type system
+async function applySchemaUpdates() {
+  console.log('🔄 Applying schema updates for new employee type system...');
+  
+  await db.run('BEGIN TRANSACTION');
+  
+  try {
+    // 1. Create employee_types table if it doesn't exist
+    await db.exec(`
+      CREATE TABLE IF NOT EXISTS employee_types (
+        type TEXT PRIMARY KEY,
+        category TEXT CHECK(category IN ('internal', 'external')) NOT NULL,
+        has_contract_type BOOLEAN NOT NULL DEFAULT FALSE
+      )
+    `);
+    
+    // 2. Insert default employee types
+    await db.run(`INSERT OR IGNORE INTO employee_types (type, category, has_contract_type) VALUES ('manager', 'internal', 1)`);
+    await db.run(`INSERT OR IGNORE INTO employee_types (type, category, has_contract_type) VALUES ('personell', 'internal', 1)`);
+    await db.run(`INSERT OR IGNORE INTO employee_types (type, category, has_contract_type) VALUES ('apprentice', 'internal', 1)`);
+    await db.run(`INSERT OR IGNORE INTO employee_types (type, category, has_contract_type) VALUES ('guest', 'external', 0)`);
+    
+    // 3. Check if employees table needs to be altered
+    const employeesTableInfo = await db.all<TableColumnInfo>(`
+      PRAGMA table_info(employees)
+    `);
+    
+    // FIXED: Check for employee_type column (not roles column)
+    const hasEmployeeType = employeesTableInfo.some((col: TableColumnInfo) => col.name === 'employee_type');
+    const hasIsTrainee = employeesTableInfo.some((col: TableColumnInfo) => col.name === 'is_trainee');
+    
+    if (!hasEmployeeType) {
+      console.log('🔄 Adding employee_type column to employees table...');
+      await db.run('ALTER TABLE employees ADD COLUMN employee_type TEXT NOT NULL DEFAULT "personell"');
+    }
+    
+    if (!hasIsTrainee) {
+      console.log('🔄 Adding is_trainee column to employees table...');
+      await db.run('ALTER TABLE employees ADD COLUMN is_trainee BOOLEAN DEFAULT FALSE NOT NULL');
+    }
+    
+    // 4. Create roles table if it doesn't exist
+    await db.exec(`
+      CREATE TABLE IF NOT EXISTS roles (
+        role TEXT PRIMARY KEY CHECK(role IN ('admin', 'user', 'maintenance')),
+        authority_level INTEGER NOT NULL UNIQUE CHECK(authority_level BETWEEN 1 AND 100),
+        description TEXT
+      )
+    `);
+    
+    // 5. Insert default roles
+    await db.run(`INSERT OR IGNORE INTO roles (role, authority_level, description) VALUES ('admin', 100, 'Vollzugriff')`);
+    await db.run(`INSERT OR IGNORE INTO roles (role, authority_level, description) VALUES ('maintenance', 50, 'Wartungszugriff')`);
+    await db.run(`INSERT OR IGNORE INTO roles (role, authority_level, description) VALUES ('user', 10, 'Standardbenutzer')`);
+    
+    // 6. Create employee_roles junction table if it doesn't exist
+    await db.exec(`
+      CREATE TABLE IF NOT EXISTS employee_roles (
+        employee_id TEXT NOT NULL REFERENCES employees(id) ON DELETE CASCADE,
+        role TEXT NOT NULL REFERENCES roles(role),
+        PRIMARY KEY (employee_id, role)
+      )
+    `);
+    
+    // 7. REMOVED: Role migration logic since roles column doesn't exist in new schema
+    // In a fresh installation, we don't need to migrate existing roles
+    
+    console.log('ℹ️ Skipping role migration - fresh installation with new schema');
+    
+    await db.run('COMMIT');
+    console.log('✅ Schema updates applied successfully');
+    
+  } catch (error) {
+    await db.run('ROLLBACK');
+    console.error('❌ Schema updates failed:', error);
+    throw error;
+  }
+}
+
 export async function applyMigration() {
   try {
     console.log('📦 Starting database migration...');
@@ -41,60 +139,68 @@ export async function applyMigration() {
     // Ensure migration tracking table exists
     await ensureMigrationTable();
     
+    // Apply schema updates for new employee type system
+    await applySchemaUpdates();
+    
     // Get all migration files
     const migrationsDir = join(__dirname, '../database/migrations');
-    const files = await readdir(migrationsDir);
     
-    // Sort files to ensure consistent order
-    const migrationFiles = files
-      .filter(f => f.endsWith('.sql'))
-      .sort();
-    
-    // Process each migration file
-    for (const migrationFile of migrationFiles) {
-      if (await isMigrationApplied(migrationFile)) {
-        console.log(`ℹ️ Migration ${migrationFile} already applied, skipping...`);
-        continue;
-      }
+    try {
+      const files = await readdir(migrationsDir);
       
-      console.log(`📄 Applying migration: ${migrationFile}`);
-      const migrationPath = join(migrationsDir, migrationFile);
-      const migrationSQL = await readFile(migrationPath, 'utf-8');
+      // Sort files to ensure consistent order
+      const migrationFiles = files
+        .filter(f => f.endsWith('.sql'))
+        .sort();
       
-      // Split into individual statements
-      const statements = migrationSQL
-        .split(';')
-        .map(s => s.trim())
-        .filter(s => s.length > 0);
-      
-      // Start transaction for this migration
-      await db.run('BEGIN TRANSACTION');
-      
-      try {
-        // Execute each statement
-        for (const statement of statements) {
-          try {
-            await db.exec(statement);
-            console.log('✅ Executed:', statement.slice(0, 50) + '...');
-          } catch (error) {
-            const err = error as { code: string; message: string };
-            if (err.code === 'SQLITE_ERROR' && err.message.includes('duplicate column name')) {
-              console.log('ℹ️ Column already exists, skipping...');
-              continue;
-            }
-            throw error;
-          }
+      // Process each migration file
+      for (const migrationFile of migrationFiles) {
+        if (await isMigrationApplied(migrationFile)) {
+          console.log(`ℹ️ Migration ${migrationFile} already applied, skipping...`);
+          continue;
         }
         
-        // Mark migration as applied
-        await markMigrationAsApplied(migrationFile);
-        await db.run('COMMIT');
-        console.log(`✅ Migration ${migrationFile} applied successfully`);
+        console.log(`📄 Applying migration: ${migrationFile}`);
+        const migrationPath = join(migrationsDir, migrationFile);
+        const migrationSQL = await readFile(migrationPath, 'utf-8');
         
-      } catch (error) {
-        await db.run('ROLLBACK');
-        throw error;
+        // Split into individual statements
+        const statements = migrationSQL
+          .split(';')
+          .map(s => s.trim())
+          .filter(s => s.length > 0);
+        
+        // Start transaction for this migration
+        await db.run('BEGIN TRANSACTION');
+        
+        try {
+          // Execute each statement
+          for (const statement of statements) {
+            try {
+              await db.exec(statement);
+              console.log('✅ Executed:', statement.slice(0, 50) + '...');
+            } catch (error) {
+              const err = error as { code: string; message: string };
+              if (err.code === 'SQLITE_ERROR' && err.message.includes('duplicate column name')) {
+                console.log('ℹ️ Column already exists, skipping...');
+                continue;
+              }
+              throw error;
+            }
+          }
+          
+          // Mark migration as applied
+          await markMigrationAsApplied(migrationFile);
+          await db.run('COMMIT');
+          console.log(`✅ Migration ${migrationFile} applied successfully`);
+          
+        } catch (error) {
+          await db.run('ROLLBACK');
+          throw error;
+        }
       }
+    } catch (error) {
+      console.log('ℹ️ No migration directory found or no migration files, skipping file-based migrations...');
     }
     
     console.log('✅ All migrations completed successfully');
diff --git a/backend/src/scripts/initializeDatabase.ts b/backend/src/scripts/initializeDatabase.ts
index 7901873..4ef1eb1 100644
--- a/backend/src/scripts/initializeDatabase.ts
+++ b/backend/src/scripts/initializeDatabase.ts
@@ -42,7 +42,7 @@ export async function initializeDatabase(): Promise<void> {
       
       console.log('Existing tables found:', existingTables.map(t => t.name).join(', ') || 'none');
       
-      // UPDATED: Drop tables in correct dependency order
+      // UPDATED: Drop tables in correct dependency order for new schema
       const tablesToDrop = [
         'employee_availability',
         'shift_assignments', 
@@ -50,9 +50,10 @@ export async function initializeDatabase(): Promise<void> {
         'shifts',
         'time_slots',
         'employee_roles',
-        'shift_plans',
         'roles',
         'employees',
+        'employee_types',
+        'shift_plans',
         'applied_migrations'
       ];
       
@@ -100,15 +101,22 @@ export async function initializeDatabase(): Promise<void> {
       }
     }
     
-    // UPDATED: Insert default roles after creating the tables
+    // UPDATED: Insert default data in correct order
     try {
+      console.log('Inserting default employee types...');
+      await db.run(`INSERT OR IGNORE INTO employee_types (type, category, has_contract_type) VALUES ('manager', 'internal', 1)`);
+      await db.run(`INSERT OR IGNORE INTO employee_types (type, category, has_contract_type) VALUES ('personell', 'internal', 1)`);
+      await db.run(`INSERT OR IGNORE INTO employee_types (type, category, has_contract_type) VALUES ('apprentice', 'internal', 1)`);
+      await db.run(`INSERT OR IGNORE INTO employee_types (type, category, has_contract_type) VALUES ('guest', 'external', 0)`);
+      console.log('✅ Default employee types inserted');
+      
       console.log('Inserting default roles...');
-      await db.run(`INSERT OR IGNORE INTO roles (role) VALUES ('admin')`);
-      await db.run(`INSERT OR IGNORE INTO roles (role) VALUES ('user')`);
-      await db.run(`INSERT OR IGNORE INTO roles (role) VALUES ('maintenance')`);
+      await db.run(`INSERT OR IGNORE INTO roles (role, authority_level, description) VALUES ('admin', 100, 'Vollzugriff')`);
+      await db.run(`INSERT OR IGNORE INTO roles (role, authority_level, description) VALUES ('maintenance', 50, 'Wartungszugriff')`);
+      await db.run(`INSERT OR IGNORE INTO roles (role, authority_level, description) VALUES ('user', 10, 'Standardbenutzer')`);
       console.log('✅ Default roles inserted');
     } catch (error) {
-      console.error('Error inserting default roles:', error);
+      console.error('Error inserting default data:', error);
       await db.run('ROLLBACK');
       throw error;
     }
diff --git a/backend/src/services/SchedulingService.ts b/backend/src/services/SchedulingService.ts
index 15c8d6a..e058eb1 100644
--- a/backend/src/services/SchedulingService.ts
+++ b/backend/src/services/SchedulingService.ts
@@ -97,16 +97,17 @@ export class SchedulingService {
       const currentDate = new Date(startDate);
       currentDate.setDate(startDate.getDate() + dayOffset);
       
-      const dayOfWeek = currentDate.getDay() === 0 ? 7 : currentDate.getDay(); // Convert Sunday from 0 to 7
+      const dayOfWeek = currentDate.getDay() === 0 ? 7 : currentDate.getDay();
       const dayShifts = shiftPlan.shifts.filter(shift => shift.dayOfWeek === dayOfWeek);
       
       dayShifts.forEach(shift => {
-        // ✅ Use day-of-week pattern instead of date-based pattern
-        const shiftId = `${shift.id}`;
+        // ✅ CRITICAL FIX: Use consistent shift ID format that matches availability lookup
+        const shiftId = `shift_${dayOfWeek}_${shift.timeSlotId}`;
+        const dateStr = currentDate.toISOString().split('T')[0];
         
         shifts.push({
-          id: shiftId, // This matches what frontend expects
-          date: currentDate.toISOString().split('T')[0],
+          id: shiftId, // This will match what availabilities are looking for
+          date: dateStr,
           timeSlotId: shift.timeSlotId,
           requiredEmployees: shift.requiredEmployees,
           minWorkers: 1,
@@ -114,7 +115,7 @@ export class SchedulingService {
           isPriority: false
         });
 
-        console.log(`✅ Generated shift: ${shiftId} for day ${dayOfWeek}, timeSlot ${shift.timeSlotId}`);
+        console.log(`✅ Generated shift: ${shiftId} for date ${dateStr}, day ${dayOfWeek}, timeSlot ${shift.timeSlotId}`);
       });
     }
 
diff --git a/backend/src/workers/scheduler-worker.ts b/backend/src/workers/scheduler-worker.ts
index f46bebb..60a1112 100644
--- a/backend/src/workers/scheduler-worker.ts
+++ b/backend/src/workers/scheduler-worker.ts
@@ -17,17 +17,42 @@ interface WorkerData {
 function buildSchedulingModel(model: CPModel, data: WorkerData): void {
   const { employees, shifts, availabilities, constraints } = data;
   
-  // Filter employees to only include active ones
-  const nonManagerEmployees = employees.filter(emp => emp.isActive && emp.employeeType !== 'manager');
-  const activeEmployees = employees.filter(emp => emp.isActive);
-  const trainees = nonManagerEmployees.filter(emp => emp.employeeType === 'trainee');
-  const experienced = nonManagerEmployees.filter(emp => emp.employeeType === 'experienced');
+  const schedulableEmployees = employees.filter(emp => 
+    emp.isActive && 
+    emp.employeeType === 'personell'
+  );
   
-  console.log(`Building model with ${nonManagerEmployees.length} employees, ${shifts.length} shifts`);
-  console.log(`Available shifts per week: ${shifts.length}`);
+  // Debug: Count constraints that will be created
+  console.log('\n🔧 CONSTRAINT ANALYSIS:');
+  let hardConstraints = 0;
+  let availabilityConstraints = 0;
+  
+  // Count availability constraints
+  schedulableEmployees.forEach((employee: any) => {
+    shifts.forEach((shift: any) => {
+      const availability = availabilities.find(
+        (a: any) => a.employeeId === employee.id && a.shiftId === shift.id
+      );
+      
+      if (!availability || availability.preferenceLevel === 3) {
+        availabilityConstraints++;
+      }
+    });
+  });
+  
+  console.log(`Availability constraints to create: ${availabilityConstraints}`);
+  console.log(`Total possible assignments: ${schedulableEmployees.length * shifts.length}`);
+  
+  const trainees = schedulableEmployees.filter(emp => emp.isTrainee);
+  const experienced = schedulableEmployees.filter(emp => !emp.isTrainee);
+  
+  console.log(`Building model with ${schedulableEmployees.length} schedulable employees, ${shifts.length} shifts`);
+  console.log(`- Trainees: ${trainees.length}`);
+  console.log(`- Experienced: ${experienced.length}`);
+  console.log(`- Excluded: ${employees.filter(emp => !emp.isActive || emp.employeeType !== 'personell').length} employees (managers, apprentices, guests, inactive)`);
 
   // 1. Create assignment variables for all possible assignments
-  nonManagerEmployees.forEach((employee: any) => {
+  schedulableEmployees.forEach((employee: any) => {
     shifts.forEach((shift: any) => {
       const varName = `assign_${employee.id}_${shift.id}`;
       model.addVariable(varName, 'bool');
@@ -35,18 +60,18 @@ function buildSchedulingModel(model: CPModel, data: WorkerData): void {
   });
 
   // 2. Availability constraints
-  nonManagerEmployees.forEach((employee: any) => {
+  schedulableEmployees.forEach((employee: any) => {
     shifts.forEach((shift: any) => {
       const availability = availabilities.find(
         (a: any) => a.employeeId === employee.id && a.shiftId === shift.id
       );
       
-      // Hard constraint: never assign when preference level is 3 (unavailable)
-      if (availability?.preferenceLevel === 3) {
-        const varName = `assign_${employee.id}_${shift.id}`;
+      const varName = `assign_${employee.id}_${shift.id}`;
+      
+      if (!availability || availability.preferenceLevel === 3) {
         model.addConstraint(
           `${varName} == 0`,
-          `Hard availability constraint for ${employee.name} in shift ${shift.id}`
+          `Employee ${employee.firstname} ${employee.lastname} has not signed up for shift ${shift.id}`
         );
       }
     });
@@ -54,7 +79,7 @@ function buildSchedulingModel(model: CPModel, data: WorkerData): void {
 
   // 3. Max 1 shift per day per employee
   const shiftsByDate = groupShiftsByDate(shifts);
-  nonManagerEmployees.forEach((employee: any) => {
+  schedulableEmployees.forEach((employee: any) => {
     Object.entries(shiftsByDate).forEach(([date, dayShifts]) => {
       const dayAssignmentVars = (dayShifts as any[]).map(
         (shift: any) => `assign_${employee.id}_${shift.id}`
@@ -71,7 +96,7 @@ function buildSchedulingModel(model: CPModel, data: WorkerData): void {
 
   // 4. Shift staffing constraints
   shifts.forEach((shift: any) => {
-    const assignmentVars = nonManagerEmployees.map(
+    const assignmentVars = schedulableEmployees.map(
       (emp: any) => `assign_${emp.id}_${shift.id}`
     );
     
@@ -117,13 +142,13 @@ function buildSchedulingModel(model: CPModel, data: WorkerData): void {
   });
 
   // 6. Employees who cannot work alone constraint
-  const employeesWhoCantWorkAlone = nonManagerEmployees.filter(emp => !emp.canWorkAlone);
+  const employeesWhoCantWorkAlone = schedulableEmployees.filter(emp => !emp.canWorkAlone);
   console.log(`Found ${employeesWhoCantWorkAlone.length} employees who cannot work alone`);
 
   employeesWhoCantWorkAlone.forEach((employee: any) => {
     shifts.forEach((shift: any) => {
       const employeeVar = `assign_${employee.id}_${shift.id}`;
-      const otherEmployees = nonManagerEmployees.filter(emp => 
+      const otherEmployees = schedulableEmployees.filter(emp => 
         emp.id !== employee.id && emp.isActive
       );
       
@@ -151,7 +176,7 @@ function buildSchedulingModel(model: CPModel, data: WorkerData): void {
   const totalShifts = shifts.length;
   console.log(`Total available shifts: ${totalShifts}`);
 
-  nonManagerEmployees.forEach((employee: any) => {
+  schedulableEmployees.forEach((employee: any) => {
     const contractType = employee.contractType || 'large';
     
     // EXACT SHIFTS PER WEEK
@@ -181,8 +206,8 @@ function buildSchedulingModel(model: CPModel, data: WorkerData): void {
   // 8. Objective: Maximize preferred assignments with soft constraints
   let objectiveExpression = '';
   let softConstraintPenalty = '';
-  
-  nonManagerEmployees.forEach((employee: any) => {
+
+  schedulableEmployees.forEach((employee: any) => {
     shifts.forEach((shift: any) => {
       const varName = `assign_${employee.id}_${shift.id}`;
       const availability = availabilities.find(
@@ -191,25 +216,28 @@ function buildSchedulingModel(model: CPModel, data: WorkerData): void {
       
       let score = 0;
       if (availability) {
-        score = availability.preferenceLevel === 1 ? 10 : 
-               availability.preferenceLevel === 2 ? 5 : 
-               -10000; // Very heavy penalty for unavailable
-      } else {
-        // No availability info - slight preference to assign
-        score = 1;
+        // Only give positive scores for shifts employees actually signed up for
+        if (availability.preferenceLevel === 1) {
+          score = 100; // High reward for preferred shifts
+        } else if (availability.preferenceLevel === 2) {
+          score = 50;  // Medium reward for available shifts
+        }
       }
-      
-      if (objectiveExpression) {
-        objectiveExpression += ` + ${score} * ${varName}`;
-      } else {
-        objectiveExpression = `${score} * ${varName}`;
+      if (score > 0) {
+        if (objectiveExpression) {
+          objectiveExpression += ` + ${score} * ${varName}`;
+        } else {
+          objectiveExpression = `${score} * ${varName}`;
+        }
       }
     });
   });
-  
+
   if (objectiveExpression) {
     model.maximize(objectiveExpression);
-    console.log('Objective function set with preference optimization');
+    console.log('Objective function set with strict availability enforcement');
+  } else {
+    console.warn('No valid objective expression could be created');
   }
 }
 
@@ -282,12 +310,12 @@ function detectViolations(assignments: any, employees: any[], shifts: any[]): st
     const assignedEmployees = assignments[shift.id] || [];
     const hasTrainee = assignedEmployees.some((empId: string) => {
       const emp = employeeMap.get(empId);
-      return emp?.employeeType === 'trainee';
+      return emp?.isTrainee;
     });
     
     const hasExperienced = assignedEmployees.some((empId: string) => {
       const emp = employeeMap.get(empId);
-      return emp?.employeeType === 'experienced';
+      return emp && !emp.isTrainee;
     });
     
     if (hasTrainee && !hasExperienced) {
@@ -330,9 +358,13 @@ function detectViolations(assignments: any, employees: any[], shifts: any[]): st
 }
 
 function assignManagersToShifts(assignments: any, managers: any[], shifts: any[], availabilities: any[]): any {
-  const managersToAssign = managers.filter(emp => emp.isActive && emp.employeeType === 'manager');
+  const managersToAssign = managers.filter(emp => 
+    emp.isActive && 
+    emp.employeeType === 'manager'
+  );
   
   console.log(`Assigning ${managersToAssign.length} managers to shifts based on availability=1`);
+  console.log(`- Excluded ${managers.filter(emp => !emp.isActive || emp.employeeType !== 'manager').length} non-manager employees from auto-assignment`);
   
   managersToAssign.forEach((manager: any) => {
     shifts.forEach((shift: any) => {
@@ -349,7 +381,7 @@ function assignManagersToShifts(assignments: any, managers: any[], shifts: any[]
         // Check if manager is already assigned (avoid duplicates)
         if (!assignments[shift.id].includes(manager.id)) {
           assignments[shift.id].push(manager.id);
-          console.log(`✅ Assigned manager ${manager.name} to shift ${shift.id} (availability=1)`);
+          console.log(`✅ Assigned manager ${manager.firstname} ${manager.lastname} to shift ${shift.id} (availability=1)`);
         }
       }
     });
@@ -375,8 +407,110 @@ async function runScheduling() {
     
     console.log(`Optimizing ${data.shifts.length} shifts for ${data.employees.length} employees`);
 
+    // 🆕 COMPREHENSIVE AVAILABILITY DEBUGGING
+    console.log('\n🔍 ===== AVAILABILITY ANALYSIS =====');
+    console.log(`Total shifts: ${data.shifts.length}`);
+    console.log(`Total availability records: ${data.availabilities.length}`);
+    
+    // Count by preference level
+    const pref1Count = data.availabilities.filter(a => a.preferenceLevel === 1).length;
+    const pref2Count = data.availabilities.filter(a => a.preferenceLevel === 2).length;
+    const pref3Count = data.availabilities.filter(a => a.preferenceLevel === 3).length;
+    
+    console.log(`Preference Level 1 (Preferred): ${pref1Count}`);
+    console.log(`Preference Level 2 (Available): ${pref2Count}`);
+    console.log(`Preference Level 3 (Unavailable): ${pref3Count}`);
+    
+    // Analyze each shift
+    console.log('\n📊 AVAILABILITIES PER SHIFT:');
+    data.shifts.forEach((shift, index) => {
+      const shiftAvailabilities = data.availabilities.filter(avail => avail.shiftId === shift.id);
+      const pref1 = shiftAvailabilities.filter(a => a.preferenceLevel === 1).length;
+      const pref2 = shiftAvailabilities.filter(a => a.preferenceLevel === 2).length;
+      const pref3 = shiftAvailabilities.filter(a => a.preferenceLevel === 3).length;
+      
+      console.log(`Shift ${index + 1}: ${shift.id}`);
+      console.log(`  📅 Date: ${shift.dayOfWeek}, TimeSlot: ${shift.timeSlotId}`);
+      console.log(`  👥 Required: ${shift.requiredEmployees}`);
+      console.log(`  ✅ Preferred (1): ${pref1}`);
+      console.log(`  🔶 Available (2): ${pref2}`);
+      console.log(`  ❌ Unavailable (3): ${pref3}`);
+      console.log(`  📋 Total signed up: ${pref1 + pref2}`);
+      
+      // Show employee names for each preference level
+      if (pref1 > 0) {
+        const pref1Employees = shiftAvailabilities
+          .filter(a => a.preferenceLevel === 1)
+          .map(a => {
+            const emp = data.employees.find(e => e.id === a.employeeId);
+            return emp ? `${emp.firstname} ${emp.lastname}` : 'Unknown';
+          });
+        console.log(`    Preferred employees: ${pref1Employees.join(', ')}`);
+      }
+      
+      if (pref2 > 0) {
+        const pref2Employees = shiftAvailabilities
+          .filter(a => a.preferenceLevel === 2)
+          .map(a => {
+            const emp = data.employees.find(e => e.id === a.employeeId);
+            return emp ? `${emp.firstname} ${emp.lastname}` : 'Unknown';
+          });
+        console.log(`    Available employees: ${pref2Employees.join(', ')}`);
+      }
+    });
+
+    // Employee-level analysis
+    console.log('\n👤 EMPLOYEE SIGNUP SUMMARY:');
+    const schedulableEmployees = data.employees.filter(emp => 
+      emp.isActive && emp.employeeType === 'personell'
+    );
+    
+    schedulableEmployees.forEach(employee => {
+      const employeeAvailabilities = data.availabilities.filter(avail => avail.employeeId === employee.id);
+      const pref1 = employeeAvailabilities.filter(a => a.preferenceLevel === 1).length;
+      const pref2 = employeeAvailabilities.filter(a => a.preferenceLevel === 2).length;
+      const pref3 = employeeAvailabilities.filter(a => a.preferenceLevel === 3).length;
+      
+      console.log(`${employee.firstname} ${employee.lastname} (${employee.contractType}):`);
+      console.log(`  ✅ Preferred: ${pref1} shifts, 🔶 Available: ${pref2} shifts, ❌ Unavailable: ${pref3} shifts`);
+    });
+
+    // Check shift ID matching
+    console.log('\n🔍 SHIFT ID MATCHING ANALYSIS:');
+    const shiftsWithNoSignups = data.shifts.filter(shift => {
+      const shiftAvailabilities = data.availabilities.filter(avail => avail.shiftId === shift.id);
+      const signedUp = shiftAvailabilities.filter(a => a.preferenceLevel === 1 || a.preferenceLevel === 2);
+      return signedUp.length === 0;
+    });
+
+    console.log(`Shifts with NO signups: ${shiftsWithNoSignups.length}/${data.shifts.length}`);
+    shiftsWithNoSignups.forEach(shift => {
+      console.log(`  ❌ No signups: ${shift.id} (${shift.dayOfWeek}, ${shift.timeSlotId})`);
+    });
+
+    console.log('===== END AVAILABILITY ANALYSIS =====\n');
+
     const nonManagerEmployees = data.employees.filter(emp => emp.isActive && emp.employeeType !== 'manager');
     
+    // Check if we have any employees who signed up for shifts
+    const employeesWithSignups = new Set(
+      data.availabilities
+        .filter(avail => avail.preferenceLevel === 1 || avail.preferenceLevel === 2)
+        .map(avail => avail.employeeId)
+    );
+
+    if (employeesWithSignups.size === 0) {
+      console.log('❌ CRITICAL: No employees have signed up for any shifts!');
+      parentPort?.postMessage({
+        assignments: {},
+        violations: ['NO_SIGNUPS: No employees have signed up for any shifts with preference level 1 or 2'],
+        success: false,
+        resolutionReport: ['❌ Scheduling failed: No employees have signed up for any shifts'],
+        processingTime: Date.now() - startTime
+      });
+      return;
+    }
+
     const model = new CPModel();
     buildSchedulingModel(model, data);
     
@@ -406,7 +540,6 @@ async function runScheduling() {
       // Extract assignments from solution (non-managers only)
       assignments = extractAssignmentsFromSolution(solution, nonManagerEmployees, data.shifts);
       
-      // 🆕 ADD THIS: Assign managers to shifts where they have availability=1
       assignments = assignManagersToShifts(assignments, data.employees, data.shifts, data.availabilities);
       
       // Only detect violations for non-manager assignments
@@ -416,7 +549,6 @@ async function runScheduling() {
         violations.push('NO_ASSIGNMENTS: Solver reported success but produced no assignments');
       }
       
-      // Update resolution report
       if (violations.length === 0) {
         resolutionReport.push('✅ No constraint violations detected for non-manager employees');
       } else {
diff --git a/frontend/src/components/Scheduler.tsx b/frontend/src/components/Scheduler.tsx
deleted file mode 100644
index 8013794..0000000
--- a/frontend/src/components/Scheduler.tsx
+++ /dev/null
@@ -1,141 +0,0 @@
-import React from 'react';
-import { useScheduling } from '../services/scheduling/useScheduling';
-import { ScheduleRequest } from '../models/scheduling';
-
-interface SchedulerProps {
-  scheduleRequest: ScheduleRequest;
-  onScheduleGenerated?: (result: any) => void;
-}
-
-export const Scheduler: React.FC<SchedulerProps> = ({ 
-  scheduleRequest, 
-  onScheduleGenerated 
-}) => {
-  const { generateSchedule, loading, error, result } = useScheduling();
-  
-  const handleGenerateSchedule = async () => {
-    try {
-      const scheduleResult = await generateSchedule(scheduleRequest);
-      if (onScheduleGenerated) {
-        onScheduleGenerated(scheduleResult);
-      }
-    } catch (err) {
-      console.error('Scheduling failed:', err);
-    }
-  };
-  
-  return (
-    <div style={{ padding: '20px', border: '1px solid #e0e0e0', borderRadius: '8px' }}>
-      <h3>Automatic Schedule Generation</h3>
-      
-      <button 
-        onClick={handleGenerateSchedule} 
-        disabled={loading}
-        style={{
-          padding: '12px 24px',
-          backgroundColor: loading ? '#95a5a6' : '#3498db',
-          color: 'white',
-          border: 'none',
-          borderRadius: '4px',
-          cursor: loading ? 'not-allowed' : 'pointer',
-          fontSize: '16px',
-          fontWeight: 'bold'
-        }}
-      >
-        {loading ? '🔄 Generating Schedule...' : '🚀 Generate Optimal Schedule'}
-      </button>
-      
-      {loading && (
-        <div style={{ marginTop: '15px' }}>
-          <div style={{ 
-            width: '100%', 
-            height: '8px', 
-            backgroundColor: '#ecf0f1', 
-            borderRadius: '4px',
-            overflow: 'hidden'
-          }}>
-            <div style={{
-              width: '70%',
-              height: '100%',
-              backgroundColor: '#3498db',
-              animation: 'pulse 2s infinite',
-              borderRadius: '4px'
-            }} />
-          </div>
-          <p style={{ color: '#7f8c8d', fontSize: '14px', marginTop: '8px' }}>
-            Optimizing schedule... (max 2 minutes)
-          </p>
-        </div>
-      )}
-      
-      {error && (
-        <div style={{
-          marginTop: '15px',
-          padding: '12px',
-          backgroundColor: '#f8d7da',
-          border: '1px solid #f5c6cb',
-          borderRadius: '4px',
-          color: '#721c24'
-        }}>
-          <strong>Error:</strong> {error}
-        </div>
-      )}
-      
-      {result && (
-        <div style={{ marginTop: '20px' }}>
-          <ScheduleResultView result={result} />
-        </div>
-      )}
-    </div>
-  );
-};
-
-const ScheduleResultView: React.FC<{ result: any }> = ({ result }) => {
-  return (
-    <div style={{
-      padding: '15px',
-      backgroundColor: result.success ? '#d4edda' : '#f8d7da',
-      border: `1px solid ${result.success ? '#c3e6cb' : '#f5c6cb'}`,
-      borderRadius: '4px'
-    }}>
-      <h4 style={{ 
-        color: result.success ? '#155724' : '#721c24',
-        marginTop: 0
-      }}>
-        {result.success ? '✅ Schedule Generated Successfully' : '❌ Schedule Generation Failed'}
-      </h4>
-      
-      <div style={{ marginBottom: '10px' }}>
-        <strong>Assignments:</strong> {Object.keys(result.assignments || {}).length} shifts assigned
-      </div>
-      
-      <div style={{ marginBottom: '10px' }}>
-        <strong>Violations:</strong> {result.violations?.length || 0}
-      </div>
-      
-      {result.resolution_report && result.resolution_report.length > 0 && (
-        <details style={{ marginTop: '10px' }}>
-          <summary style={{ cursor: 'pointer', fontWeight: 'bold' }}>
-            Resolution Report
-          </summary>
-          <div style={{ 
-            marginTop: '10px', 
-            maxHeight: '200px', 
-            overflow: 'auto',
-            fontSize: '12px',
-            fontFamily: 'monospace',
-            backgroundColor: 'rgba(0,0,0,0.05)',
-            padding: '10px',
-            borderRadius: '4px'
-          }}>
-            {result.resolution_report.map((line: string, index: number) => (
-              <div key={index} style={{ marginBottom: '2px' }}>{line}</div>
-            ))}
-          </div>
-        </details>
-      )}
-    </div>
-  );
-};
-
-export default Scheduler;
\ No newline at end of file
diff --git a/frontend/src/contexts/AuthContext.tsx b/frontend/src/contexts/AuthContext.tsx
index 9b5c59b..61eac0d 100644
--- a/frontend/src/contexts/AuthContext.tsx
+++ b/frontend/src/contexts/AuthContext.tsx
@@ -165,7 +165,7 @@ export const AuthProvider: React.FC<AuthProviderProps> = ({ children }) => {
     refreshUser,
     needsSetup: needsSetup === null ? true : needsSetup,
     checkSetupStatus,
-    updateUser, // Add this to the context value
+    updateUser,
   };
 
   return (
diff --git a/frontend/src/models/Employee.ts b/frontend/src/models/Employee.ts
index 7833780..6cfcb29 100644
--- a/frontend/src/models/Employee.ts
+++ b/frontend/src/models/Employee.ts
@@ -4,10 +4,11 @@ export interface Employee {
   email: string;
   firstname: string;
   lastname: string;
-  employeeType: 'manager' | 'trainee' | 'experienced';
-  contractType: 'small' | 'large';
+  employeeType: 'manager' | 'personell' | 'apprentice' | 'guest';
+  contractType?: 'small' | 'large' | 'flexible';
   canWorkAlone: boolean;
   isActive: boolean;
+  isTrainee: boolean;
   createdAt: string;
   lastLogin?: string | null;
   roles?: string[];
@@ -17,20 +18,22 @@ export interface CreateEmployeeRequest {
   password: string;
   firstname: string;
   lastname: string;
-  roles: string[];
-  employeeType: 'manager' | 'trainee' | 'experienced';
-  contractType: 'small' | 'large';
+  roles?: string[];
+  employeeType: 'manager' | 'personell' | 'apprentice' | 'guest';
+  contractType?: 'small' | 'large' | 'flexible';
   canWorkAlone: boolean;
+  isTrainee?: boolean;
 }
 
 export interface UpdateEmployeeRequest {
   firstname?: string;
   lastname?: string;
   roles?: string[];
-  employeeType?: 'manager' | 'trainee' | 'experienced';
-  contractType?: 'small' | 'large';
+  employeeType?: 'manager' | 'personell' | 'apprentice' | 'guest';
+  contractType?: 'small' | 'large' | 'flexible';
   canWorkAlone?: boolean;
   isActive?: boolean;
+  isTrainee?: boolean;
 }
 
 export interface EmployeeWithPassword extends Employee {
@@ -41,7 +44,7 @@ export interface EmployeeAvailability {
   id: string;
   employeeId: string;
   planId: string;
-  shiftId: string; // Now references shift_id instead of time_slot_id + day_of_week
+  shiftId: string;
   preferenceLevel: 1 | 2 | 3; // 1:preferred, 2:available, 3:unavailable
   notes?: string;
 }
@@ -83,4 +86,11 @@ export interface Role {
 export interface EmployeeRole {
   employeeId: string;
   role: 'admin' | 'user' | 'maintenance';
+}
+
+// Employee type configuration
+export interface EmployeeType {
+  type: 'manager' | 'personell' | 'apprentice' | 'guest';
+  category: 'internal' | 'external';
+  has_contract_type: boolean;
 }
\ No newline at end of file
diff --git a/frontend/src/models/defaults/employeeDefaults.ts b/frontend/src/models/defaults/employeeDefaults.ts
index 7a61cae..e80e189 100644
--- a/frontend/src/models/defaults/employeeDefaults.ts
+++ b/frontend/src/models/defaults/employeeDefaults.ts
@@ -4,19 +4,41 @@ import { EmployeeAvailability, ManagerAvailability } from '../Employee.js';
 // Default employee data for quick creation
 export const EMPLOYEE_DEFAULTS = {
   role: 'user' as const,
-  employeeType: 'experienced' as const,
+  employeeType: 'personell' as const,
   contractType: 'small' as const,
   canWorkAlone: false,
-  isActive: true
+  isActive: true,
+  isTrainee: false
 };
 
 // Manager-specific defaults
 export const MANAGER_DEFAULTS = {
   role: 'admin' as const,
   employeeType: 'manager' as const,
-  contractType: 'large' as const,
+  contractType: 'flexible' as const,
   canWorkAlone: true,
-  isActive: true
+  isActive: true,
+  isTrainee: false
+};
+
+// Apprentice defaults
+export const APPRENTICE_DEFAULTS = {
+  role: 'user' as const,
+  employeeType: 'apprentice' as const,
+  contractType: 'flexible' as const,
+  canWorkAlone: false,
+  isActive: true,
+  isTrainee: false
+};
+
+// Guest defaults
+export const GUEST_DEFAULTS = {
+  role: 'user' as const,
+  employeeType: 'guest' as const,
+  contractType: undefined,
+  canWorkAlone: false,
+  isActive: true,
+  isTrainee: false
 };
 
 export const EMPLOYEE_TYPE_CONFIG = {
@@ -24,22 +46,37 @@ export const EMPLOYEE_TYPE_CONFIG = {
     value: 'manager' as const,
     label: 'Chef/Administrator', 
     color: '#e74c3c',
+    category: 'internal' as const,
+    hasContractType: true,
     independent: true,
     description: 'Vollzugriff auf alle Funktionen und Mitarbeiterverwaltung'
   },
-  experienced: { 
-    value: 'experienced' as const,
-    label: 'Erfahren', 
+  personell: { 
+    value: 'personell' as const,
+    label: 'Personal', 
     color: '#3498db',
+    category: 'internal' as const,
+    hasContractType: true,
     independent: true,
-    description: 'Langjährige Erfahrung, kann komplexe Aufgaben übernehmen'
+    description: 'Reguläre Mitarbeiter mit Vertrag'
   },
-  trainee: { 
-    value: 'trainee' as const,
-    label: 'Neuling', 
-    color: '#27ae60', 
+  apprentice: { 
+    value: 'apprentice' as const,
+    label: 'Auszubildender', 
+    color: '#9b59b6',
+    category: 'internal' as const,
+    hasContractType: true,
     independent: false,
-    description: 'Benötigt Einarbeitung und Unterstützung'
+    description: 'Auszubildende mit flexiblem Vertrag'
+  },
+  guest: { 
+    value: 'guest' as const,
+    label: 'Gast', 
+    color: '#95a5a6',
+    category: 'external' as const,
+    hasContractType: false,
+    independent: false,
+    description: 'Externe Mitarbeiter ohne Vertrag'
   }
 } as const;
 
@@ -53,9 +90,10 @@ export const ROLE_CONFIG = [
 export const CONTRACT_TYPE_DESCRIPTIONS = {
   small: '1 Schicht pro Woche',
   large: '2 Schichten pro Woche',
-  manager: 'Kein Vertragslimit - Immer MO und DI verfügbar'
+  flexible: 'Flexible Arbeitszeiten'
 } as const;
 
+
 // Availability preference descriptions
 export const AVAILABILITY_PREFERENCES = {
   1: { label: 'Bevorzugt', color: '#10b981', description: 'Möchte diese Schicht arbeiten' },
@@ -104,4 +142,17 @@ export function createManagerDefaultSchedule(managerId: string, planId: string,
   }
   
   return assignments;
+}
+
+export function getDefaultsByEmployeeType(employeeType: string) {
+  switch (employeeType) {
+    case 'manager':
+      return MANAGER_DEFAULTS;
+    case 'apprentice':
+      return APPRENTICE_DEFAULTS;
+    case 'guest':
+      return GUEST_DEFAULTS;
+    default:
+      return EMPLOYEE_DEFAULTS;
+  }
 }
\ No newline at end of file
diff --git a/frontend/src/models/helpers/employeeHelpers.ts b/frontend/src/models/helpers/employeeHelpers.ts
index 5b55f12..63b4f45 100644
--- a/frontend/src/models/helpers/employeeHelpers.ts
+++ b/frontend/src/models/helpers/employeeHelpers.ts
@@ -1,9 +1,8 @@
 // backend/src/models/helpers/employeeHelpers.ts
 import { Employee, CreateEmployeeRequest, EmployeeAvailability } from '../Employee.js';
 
-// Email generation function (same as in controllers)
+// Email generation function
 function generateEmail(firstname: string, lastname: string): string {
-  // Convert German umlauts to their expanded forms
   const convertUmlauts = (str: string): string => {
     return str
       .toLowerCase()
@@ -13,19 +12,16 @@ function generateEmail(firstname: string, lastname: string): string {
       .replace(/ß/g, 'ss');
   };
 
-  // Remove any remaining special characters and convert to lowercase
   const cleanFirstname = convertUmlauts(firstname).replace(/[^a-z0-9]/g, '');
   const cleanLastname = convertUmlauts(lastname).replace(/[^a-z0-9]/g, '');
   
   return `${cleanFirstname}.${cleanLastname}@sp.de`;
 }
 
-// UPDATED: Validation for new employee model
+// UPDATED: Validation for new employee model with employee types
 export function validateEmployeeData(employee: CreateEmployeeRequest): string[] {
   const errors: string[] = [];
 
-  // Email is now auto-generated, so no email validation needed
-  
   if (employee.password?.length < 6) {
     errors.push('Password must be at least 6 characters long');
   }
@@ -38,24 +34,70 @@ export function validateEmployeeData(employee: CreateEmployeeRequest): string[]
     errors.push('Last name is required and must be at least 2 characters long');
   }
 
+  // Validate employee type
+  const validEmployeeTypes = ['manager', 'personell', 'apprentice', 'guest'];
+  if (!employee.employeeType || !validEmployeeTypes.includes(employee.employeeType)) {
+    errors.push(`Employee type must be one of: ${validEmployeeTypes.join(', ')}`);
+  }
+
+  // Validate contract type based on employee type
+  if (employee.employeeType !== 'guest') {
+    // Internal types require contract type
+    if (!employee.contractType) {
+      errors.push(`Contract type is required for employee type: ${employee.employeeType}`);
+    } else {
+      const validContractTypes = ['small', 'large', 'flexible'];
+      if (!validContractTypes.includes(employee.contractType)) {
+        errors.push(`Contract type must be one of: ${validContractTypes.join(', ')}`);
+      }
+    }
+  } else {
+    // External types (guest) should not have contract type
+    if (employee.contractType) {
+      errors.push('Contract type is not allowed for guest employees');
+    }
+  }
+
+  // Validate isTrainee - only applicable for personell type
+  if (employee.isTrainee && employee.employeeType !== 'personell') {
+    errors.push('isTrainee is only allowed for personell employee type');
+  }
+
   return errors;
 }
 
-// Generate email for employee (new helper function)
+// Generate email for employee
 export function generateEmployeeEmail(firstname: string, lastname: string): string {
   return generateEmail(firstname, lastname);
 }
 
-// Simplified business logic helpers
+// UPDATED: Business logic helpers for new employee types
 export const isManager = (employee: Employee): boolean => 
   employee.employeeType === 'manager';
 
+export const isPersonell = (employee: Employee): boolean => 
+  employee.employeeType === 'personell';
+
+export const isApprentice = (employee: Employee): boolean => 
+  employee.employeeType === 'apprentice';
+
+export const isGuest = (employee: Employee): boolean => 
+  employee.employeeType === 'guest';
+
+export const isInternal = (employee: Employee): boolean =>
+  ['manager', 'personell', 'apprentice'].includes(employee.employeeType);
+
+export const isExternal = (employee: Employee): boolean =>
+  employee.employeeType === 'guest';
+
+// UPDATED: Trainee logic - now based on isTrainee field for personell type
 export const isTrainee = (employee: Employee): boolean => 
-  employee.employeeType === 'trainee';
+  employee.employeeType === 'personell' && employee.isTrainee;
 
 export const isExperienced = (employee: Employee): boolean => 
-  employee.employeeType === 'experienced';
+  employee.employeeType === 'personell' && !employee.isTrainee;
 
+// Role-based helpers
 export const isAdmin = (employee: Employee): boolean => 
   employee.roles?.includes('admin') || false;
 
@@ -64,13 +106,12 @@ export const isMaintenance = (employee: Employee): boolean =>
 
 export const isUser = (employee: Employee): boolean => 
   employee.roles?.includes('user') || false;
+
+// UPDATED: Work alone permission - managers and experienced personell can work alone
 export const canEmployeeWorkAlone = (employee: Employee): boolean => 
-  employee.canWorkAlone && isExperienced(employee);
+  employee.canWorkAlone && (isManager(employee) || isExperienced(employee));
 
-export const getEmployeeWorkHours = (employee: Employee): number =>
-  isManager(employee) ? 999 : (employee.contractType === 'small' ? 1 : 2);
-
-// New helper for full name display
+// Helper for full name display
 export const getFullName = (employee: { firstname: string; lastname: string }): string =>
   `${employee.firstname} ${employee.lastname}`;
 
@@ -91,4 +132,14 @@ export function validateAvailabilityData(availability: Omit<EmployeeAvailability
   }
 
   return errors;
-}
\ No newline at end of file
+}
+
+// UPDATED: Helper to get employee type category
+export const getEmployeeCategory = (employee: Employee): 'internal' | 'external' => {
+  return isInternal(employee) ? 'internal' : 'external';
+};
+
+// Helper to check if employee requires contract type
+export const requiresContractType = (employee: Employee): boolean => {
+  return isInternal(employee);
+};
\ No newline at end of file
diff --git a/frontend/src/models/scheduling.ts b/frontend/src/models/scheduling.ts
index 5943cc1..b8a9c14 100644
--- a/frontend/src/models/scheduling.ts
+++ b/frontend/src/models/scheduling.ts
@@ -7,10 +7,10 @@ export interface Availability {
   id: string;
   employeeId: string;
   planId: string;
-  shiftId: string; // Now references shift_id instead of time_slot_id + day_of_week
-  preferenceLevel: 1 | 2 | 3; // 1:preferred, 2:available, 3:unavailable
+  shiftId: string;
+  preferenceLevel: 1 | 2 | 3;
   notes?: string;
-  // Optional convenience fields (can be joined from shifts and time_slots tables)
+  // Optional convenience fields
   dayOfWeek?: number;
   timeSlotId?: string;
   timeSlotName?: string;
@@ -30,7 +30,7 @@ export interface Constraint {
     maxHoursPerWeek?: number;
     [key: string]: any;
   };
-  weight?: number; // For soft constraints
+  weight?: number;
 }
 
 export interface ScheduleRequest {
@@ -153,8 +153,9 @@ export interface AvailabilityWithDetails extends Availability {
     id: string;
     firstname: string;
     lastname: string;
-    employeeType: 'manager' | 'trainee' | 'experienced';
+    employeeType: 'manager' | 'personell' | 'apprentice' | 'guest';
     canWorkAlone: boolean;
+    isTrainee: boolean;
   };
   shift?: {
     dayOfWeek: number;
diff --git a/frontend/src/pages/Auth/Login.tsx b/frontend/src/pages/Auth/Login.tsx
index ccc0513..cad7cfa 100644
--- a/frontend/src/pages/Auth/Login.tsx
+++ b/frontend/src/pages/Auth/Login.tsx
@@ -3,6 +3,7 @@ import React, { useState, useEffect } from 'react';
 import { useNavigate } from 'react-router-dom';
 import { useAuth } from '../../contexts/AuthContext';
 import { useNotification } from '../../contexts/NotificationContext';
+import { employeeService } from '../../services/employeeService';
 
 const Login: React.FC = () => {
   const [email, setEmail] = useState('');
@@ -12,7 +13,6 @@ const Login: React.FC = () => {
   const { showNotification } = useNotification();
   const navigate = useNavigate();
 
-  // 🔥 NEU: Redirect wenn bereits eingeloggt
   useEffect(() => {
     if (user) {
       console.log('✅ User already logged in, redirecting to dashboard');
@@ -27,8 +27,7 @@ const Login: React.FC = () => {
     try {
       console.log('🔐 Attempting login for:', email);
       await login({ email, password });
-      
-      // 🔥 WICHTIG: Erfolgsmeldung und Redirect
+
       console.log('✅ Login successful, redirecting to dashboard');
       showNotification({
         type: 'success',
diff --git a/frontend/src/pages/Dashboard/Dashboard.tsx b/frontend/src/pages/Dashboard/Dashboard.tsx
index 74b8399..a246eb6 100644
--- a/frontend/src/pages/Dashboard/Dashboard.tsx
+++ b/frontend/src/pages/Dashboard/Dashboard.tsx
@@ -20,6 +20,7 @@ interface DashboardData {
   }>;
   teamStats: {
     totalEmployees: number;
+    personell: number;
     manager: number;
     trainee: number;
     experienced: number;
@@ -36,6 +37,7 @@ const Dashboard: React.FC = () => {
     upcomingShifts: [],
     teamStats: {
       totalEmployees: 0,
+      personell: 0,
       manager: 0,
       trainee: 0,
       experienced: 0
@@ -208,11 +210,13 @@ const Dashboard: React.FC = () => {
 
     // Count by type
     const managerCount = employees.filter(e => e.employeeType === 'manager').length;
-    const traineeCount = employees.filter(e => e.employeeType === 'trainee').length;
-    const experiencedCount = employees.filter(e => e.employeeType === 'experienced').length;
+    const personellCount = employees.filter(e => e.employeeType === 'personell').length;
+    const traineeCount = employees.filter(e => e.isTrainee === true).length;
+    const experiencedCount = employees.filter(e => e.isTrainee === false).length;
 
     return {
       totalEmployees,
+      personell: personellCount,
       manager: managerCount,
       trainee: traineeCount,
       experienced: experiencedCount,
@@ -538,7 +542,7 @@ const Dashboard: React.FC = () => {
           <h3 style={{ margin: '0 0 15px 0', color: '#2c3e50' }}>👥 Team-Übersicht</h3>
           <div style={{ display: 'grid', gap: '12px' }}>
             <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}>
-              <span>Mitarbeiter:</span>
+              <span>Gesamte Belegschaft:</span>
               <span style={{ fontWeight: 'bold', fontSize: '18px' }}>
                 {data.teamStats.totalEmployees}
               </span>
@@ -550,15 +554,9 @@ const Dashboard: React.FC = () => {
               </span>
             </div>
             <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}>
-              <span>Erfahrene:</span>
+              <span>Personal:</span>
               <span style={{ fontWeight: 'bold', color: '#f39c12' }}>
-                {data.teamStats.experienced}
-              </span>
-            </div>
-            <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}>
-              <span>Neue:</span>
-              <span style={{ fontWeight: 'bold', color: '#e74c3c' }}>
-                {data.teamStats.trainee}
+                {data.teamStats.personell}
               </span>
             </div>
           </div>
diff --git a/frontend/src/pages/Employees/components/AvailabilityManager.tsx b/frontend/src/pages/Employees/components/AvailabilityManager.tsx
index 5090407..1331ea6 100644
--- a/frontend/src/pages/Employees/components/AvailabilityManager.tsx
+++ b/frontend/src/pages/Employees/components/AvailabilityManager.tsx
@@ -54,15 +54,122 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
     { level: 3 as AvailabilityLevel, label: 'Nicht möglich', color: '#e74c3c', bgColor: '#fadbd8', description: 'Nicht verfügbar' }
   ];
 
+  // Lade initial die Schichtpläne
   useEffect(() => {
-    loadData();
+    const loadInitialData = async () => {
+      try {
+        setLoading(true);
+        console.log('🔄 LADE INITIALDATEN FÜR MITARBEITER:', employee.id);
+        
+        // 1. Lade alle Schichtpläne
+        const plans = await shiftPlanService.getShiftPlans();
+        console.log('✅ SCHICHTPLÄNE GELADEN:', plans.length);
+        setShiftPlans(plans);
+
+        // 2. Wähle ersten verfügbaren Plan aus
+        if (plans.length > 0) {
+          const planWithShifts = plans.find(plan => 
+            plan.shifts && plan.shifts.length > 0 && 
+            plan.timeSlots && plan.timeSlots.length > 0
+          ) || plans[0];
+          
+          console.log('✅ ERSTER PLAN AUSGEWÄHLT:', planWithShifts.name);
+          setSelectedPlanId(planWithShifts.id);
+        } else {
+          setLoading(false);
+        }
+
+      } catch (err: any) {
+        console.error('❌ FEHLER BEIM LADEN DER INITIALDATEN:', err);
+        setError('Daten konnten nicht geladen werden: ' + (err.message || 'Unbekannter Fehler'));
+        setLoading(false);
+      }
+    };
+
+    loadInitialData();
   }, [employee.id]);
 
+  // Lade Plan-Details und Verfügbarkeiten wenn selectedPlanId sich ändert
   useEffect(() => {
-    if (selectedPlanId) {
-      loadSelectedPlan();
-    }
-  }, [selectedPlanId]);
+    const loadPlanData = async () => {
+      if (!selectedPlanId) {
+        setLoading(false);
+        return;
+      }
+
+      try {
+        setLoading(true);
+        console.log('🔄 LADE PLAN-DATEN FÜR:', selectedPlanId);
+        
+        // 1. Lade Schichtplan Details
+        const plan = await shiftPlanService.getShiftPlan(selectedPlanId);
+        setSelectedPlan(plan);
+        console.log('✅ SCHICHTPLAN DETAILS GELADEN:', {
+          name: plan.name,
+          timeSlotsCount: plan.timeSlots?.length || 0,
+          shiftsCount: plan.shifts?.length || 0,
+          usedDays: Array.from(new Set(plan.shifts?.map(s => s.dayOfWeek) || [])).sort()
+        });
+
+        // 2. Lade Verfügbarkeiten für DIESEN Mitarbeiter und DIESEN Plan
+        console.log('🔄 LADE VERFÜGBARKEITEN FÜR:', {
+          employeeId: employee.id,
+          planId: selectedPlanId
+        });
+
+        try {
+          const allAvailabilities = await employeeService.getAvailabilities(employee.id);
+          console.log('📋 ALLE VERFÜGBARKEITEN DES MITARBEITERS:', allAvailabilities.length);
+          
+          // Filtere nach dem aktuellen Plan UND stelle sicher, dass shiftId vorhanden ist
+          const planAvailabilities = allAvailabilities.filter(
+            avail => avail.planId === selectedPlanId && avail.shiftId
+          );
+          
+          console.log('✅ VERFÜGBARKEITEN FÜR DIESEN PLAN (MIT SHIFT-ID):', planAvailabilities.length);
+          
+          // Debug: Zeige auch ungültige Einträge
+          const invalidAvailabilities = allAvailabilities.filter(
+            avail => avail.planId === selectedPlanId && !avail.shiftId
+          );
+          if (invalidAvailabilities.length > 0) {
+            console.warn('⚠️ UNGÜLTIGE VERFÜGBARKEITEN (OHNE SHIFT-ID):', invalidAvailabilities.length);
+            invalidAvailabilities.forEach(invalid => {
+              console.warn('   - Ungültiger Eintrag:', invalid);
+            });
+          }
+          
+          // Transformiere die Daten
+          const transformedAvailabilities: Availability[] = planAvailabilities.map(avail => ({
+            ...avail,
+            isAvailable: avail.preferenceLevel !== 3
+          }));
+          
+          setAvailabilities(transformedAvailabilities);
+
+          // Debug: Zeige vorhandene Präferenzen
+          if (planAvailabilities.length > 0) {
+            console.log('🎯 VORHANDENE PRÄFERENZEN:');
+            planAvailabilities.forEach(avail => {
+              const shift = plan.shifts?.find(s => s.id === avail.shiftId);
+              console.log(`   - Shift: ${avail.shiftId} (Day: ${shift?.dayOfWeek}), Level: ${avail.preferenceLevel}`);
+            });
+          }
+      } catch (availError) {
+        console.error('❌ FEHLER BEIM LADEN DER VERFÜGBARKEITEN:', availError);
+        setAvailabilities([]);
+      }
+
+      } catch (err: any) {
+        console.error('❌ FEHLER BEIM LADEN DES SCHICHTPLANS:', err);
+        setError('Schichtplan konnte nicht geladen werden: ' + (err.message || 'Unbekannter Fehler'));
+      } finally {
+        setLoading(false);
+      }
+    };
+
+    loadPlanData();
+  }, [selectedPlanId, employee.id]);
 
   const formatTime = (time: string): string => {
     if (!time) return '--:--';
@@ -116,73 +223,12 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
     return { days, shiftsByDay };
   };
 
-  const loadData = async () => {
-    try {
-      setLoading(true);
-      console.log('🔄 LADE DATEN FÜR MITARBEITER:', employee.id);
-      
-      // 1. Load availabilities
-      let existingAvailabilities: Availability[] = [];
-      try {
-        const availabilitiesData = await employeeService.getAvailabilities(employee.id);
-        existingAvailabilities = availabilitiesData.map(avail => ({
-          ...avail,
-          isAvailable: avail.preferenceLevel !== 3
-        }));
-        console.log('✅ VERFÜGBARKEITEN GELADEN:', existingAvailabilities.length);
-      } catch (err) {
-        console.log('⚠️ KEINE VERFÜGBARKEITEN GEFUNDEN ODER FEHLER:', err);
-      }
-
-      // 2. Load shift plans
-      console.log('🔄 LADE SCHICHTPLÄNE...');
-      const plans = await shiftPlanService.getShiftPlans();
-      console.log('✅ SCHICHTPLÄNE GELADEN:', plans.length);
-
-      setShiftPlans(plans);
-
-      // 3. Select first plan with actual shifts if available
-      if (plans.length > 0) {
-        const planWithShifts = plans.find(plan => 
-          plan.shifts && plan.shifts.length > 0 && 
-          plan.timeSlots && plan.timeSlots.length > 0
-        ) || plans[0];
-        
-        setSelectedPlanId(planWithShifts.id);
-        console.log('✅ SCHICHTPLAN AUSGEWÄHLT:', planWithShifts.name);
-        
-        await loadSelectedPlan();
-      }
-
-      // 4. Set existing availabilities
-      setAvailabilities(existingAvailabilities);
-
-    } catch (err: any) {
-      console.error('❌ FEHLER BEIM LADEN DER DATEN:', err);
-      setError('Daten konnten nicht geladen werden: ' + (err.message || 'Unbekannter Fehler'));
-    } finally {
-      setLoading(false);
-    }
-  };
-
-  const loadSelectedPlan = async () => {
-    try {
-      console.log('🔄 LADE AUSGEWÄHLTEN SCHICHTPLAN:', selectedPlanId);
-      const plan = await shiftPlanService.getShiftPlan(selectedPlanId);
-      setSelectedPlan(plan);
-      console.log('✅ SCHICHTPLAN GELADEN:', {
-        name: plan.name,
-        timeSlotsCount: plan.timeSlots?.length || 0,
-        shiftsCount: plan.shifts?.length || 0,
-        usedDays: Array.from(new Set(plan.shifts?.map(s => s.dayOfWeek) || [])).sort()
-      });
-    } catch (err: any) {
-      console.error('❌ FEHLER BEIM LADEN DES SCHICHTPLANS:', err);
-      setError('Schichtplan konnte nicht geladen werden: ' + (err.message || 'Unbekannter Fehler'));
-    }
-  };
-
   const handleAvailabilityLevelChange = (shiftId: string, level: AvailabilityLevel) => {
+    if (!shiftId) {
+      console.error('❌ Versuch, Verfügbarkeit ohne Shift-ID zu ändern');
+      return;
+    }
+    
     console.log(`🔄 ÄNDERE VERFÜGBARKEIT: Shift ${shiftId}, Level ${level}`);
     
     setAvailabilities(prev => {
@@ -238,24 +284,56 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
       );
     }
 
-    // Get all unique shifts across all days for row headers
-    const allShifts: ExtendedShift[] = [];
-    const shiftIds = new Set<string>();
-    
+    // Create a map for quick time slot lookups
+    const timeSlotMap = new Map(selectedPlan?.timeSlots?.map(ts => [ts.id, ts]) || []);
+
+    // Get all unique time slots (rows) by collecting from all shifts
+    const allTimeSlots = new Map();
     days.forEach(day => {
       shiftsByDay[day.id]?.forEach(shift => {
-        if (!shiftIds.has(shift.id)) {
-          shiftIds.add(shift.id);
-          allShifts.push(shift);
+        const timeSlot = timeSlotMap.get(shift.timeSlotId);
+        if (timeSlot && !allTimeSlots.has(timeSlot.id)) {
+          allTimeSlots.set(timeSlot.id, {
+            ...timeSlot,
+            shiftsByDay: {} // Initialize empty object to store shifts by day
+          });
         }
       });
     });
 
-    // Sort shifts by time slot start time
-    allShifts.sort((a, b) => {
-      const timeA = a.startTime || '';
-      const timeB = b.startTime || '';
-      return timeA.localeCompare(timeB);
+    // Populate shifts for each time slot by day
+    days.forEach(day => {
+      shiftsByDay[day.id]?.forEach(shift => {
+        const timeSlot = allTimeSlots.get(shift.timeSlotId);
+        if (timeSlot) {
+          timeSlot.shiftsByDay[day.id] = shift;
+        }
+      });
+    });
+
+    // Convert to array and sort by start time
+    const sortedTimeSlots = Array.from(allTimeSlots.values()).sort((a, b) => {
+      return (a.startTime || '').localeCompare(b.startTime || '');
+    });
+
+    // Validation: Check if shifts are correctly placed
+    const validationErrors: string[] = [];
+    
+    // Check for missing time slots
+    const usedTimeSlotIds = new Set(selectedPlan?.shifts?.map(s => s.timeSlotId) || []);
+    const availableTimeSlotIds = new Set(selectedPlan?.timeSlots?.map(ts => ts.id) || []);
+    
+    usedTimeSlotIds.forEach(timeSlotId => {
+      if (!availableTimeSlotIds.has(timeSlotId)) {
+        validationErrors.push(`Zeitslot ${timeSlotId} wird verwendet, existiert aber nicht in timeSlots`);
+      }
+    });
+
+    // Check for shifts with invalid day numbers
+    selectedPlan?.shifts?.forEach(shift => {
+      if (shift.dayOfWeek < 1 || shift.dayOfWeek > 7) {
+        validationErrors.push(`Shift ${shift.id} hat ungültigen Wochentag: ${shift.dayOfWeek}`);
+      }
     });
 
     return (
@@ -273,10 +351,39 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
         }}>
           Verfügbarkeit definieren
           <div style={{ fontSize: '14px', fontWeight: 'normal', marginTop: '5px' }}>
-            {allShifts.length} Schichten • {days.length} Tage • Direkte Shift-ID Zuordnung
+            {sortedTimeSlots.length} Zeitslots • {days.length} Tage • Zeitbasierte Darstellung
           </div>
         </div>
 
+        {/* Validation Warnings */}
+        {validationErrors.length > 0 && (
+          <div style={{
+            backgroundColor: '#fff3cd',
+            border: '1px solid #ffeaa7',
+            padding: '15px',
+            margin: '10px'
+          }}>
+            <h4 style={{ margin: '0 0 10px 0', color: '#856404' }}>⚠️ Validierungswarnungen:</h4>
+            <ul style={{ margin: 0, paddingLeft: '20px', fontSize: '12px' }}>
+              {validationErrors.map((error, index) => (
+                <li key={index}>{error}</li>
+              ))}
+            </ul>
+          </div>
+        )}
+
+        {/* Timetable Structure Info */}
+        <div style={{
+          backgroundColor: '#d1ecf1',
+          border: '1px solid #bee5eb',
+          padding: '10px 15px',
+          margin: '10px',
+          borderRadius: '4px',
+          fontSize: '12px'
+        }}>
+          <strong>Struktur-Info:</strong> {sortedTimeSlots.length} Zeitslots × {days.length} Tage = {sortedTimeSlots.length * days.length} Zellen
+        </div>
+
         <div style={{ overflowX: 'auto' }}>
           <table style={{
             width: '100%',
@@ -290,9 +397,9 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
                   textAlign: 'left',
                   border: '1px solid #dee2e6',
                   fontWeight: 'bold',
-                  minWidth: '150px'
+                  minWidth: '200px'
                 }}>
-                  Schicht (Zeit)
+                  Zeitslot
                 </th>
                 {days.map(weekday => (
                   <th key={weekday.id} style={{
@@ -300,7 +407,7 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
                     textAlign: 'center',
                     border: '1px solid #dee2e6',
                     fontWeight: 'bold',
-                    minWidth: '90px'
+                    minWidth: '120px'
                   }}>
                     {weekday.name}
                   </th>
@@ -308,26 +415,32 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
               </tr>
             </thead>
             <tbody>
-              {allShifts.map((shift, shiftIndex) => (
-                <tr key={shift.id} style={{
-                  backgroundColor: shiftIndex % 2 === 0 ? 'white' : '#f8f9fa'
+              {sortedTimeSlots.map((timeSlot, timeSlotIndex) => (
+                <tr key={timeSlot.id} style={{
+                  backgroundColor: timeSlotIndex % 2 === 0 ? 'white' : '#f8f9fa'
                 }}>
                   <td style={{
                     padding: '12px 16px',
                     border: '1px solid #dee2e6',
                     fontWeight: '500',
-                    backgroundColor: '#f8f9fa'
+                    backgroundColor: '#f8f9fa',
+                    position: 'sticky',
+                    left: 0
                   }}>
-                    {shift.displayName}
-                    <div style={{ fontSize: '11px', color: '#666', marginTop: '4px' }}>
-                      Shift-ID: {shift.id.substring(0, 8)}...
+                    <div style={{ fontWeight: 'bold' }}>
+                      {timeSlot.name}
+                    </div>
+                    <div style={{ fontSize: '14px', color: '#666' }}>
+                      {formatTime(timeSlot.startTime)} - {formatTime(timeSlot.endTime)}
+                    </div>
+                    <div style={{ fontSize: '11px', color: '#999', marginTop: '4px' }}>
+                      ID: {timeSlot.id.substring(0, 8)}...
                     </div>
                   </td>
                   {days.map(weekday => {
-                    // Check if this shift exists for this day
-                    const shiftForDay = shiftsByDay[weekday.id]?.find(s => s.id === shift.id);
+                    const shift = timeSlot.shiftsByDay[weekday.id];
                     
-                    if (!shiftForDay) {
+                    if (!shift) {
                       return (
                         <td key={weekday.id} style={{
                           padding: '12px 16px',
@@ -337,11 +450,14 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
                           color: '#ccc',
                           fontStyle: 'italic'
                         }}>
-                          -
+                          Kein Shift
                         </td>
                       );
                     }
 
+                    // Validation: Check if shift has correct timeSlotId and dayOfWeek
+                    const isValidShift = shift.timeSlotId === timeSlot.id && shift.dayOfWeek === weekday.id;
+                    
                     const currentLevel = getAvailabilityForShift(shift.id);
                     const levelConfig = availabilityLevels.find(l => l.level === currentLevel);
                     
@@ -350,8 +466,31 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
                         padding: '12px 16px',
                         border: '1px solid #dee2e6',
                         textAlign: 'center',
-                        backgroundColor: levelConfig?.bgColor
+                        backgroundColor: !isValidShift ? '#fff3cd' : (levelConfig?.bgColor || 'white'),
+                        position: 'relative'
                       }}>
+                        {/* Validation indicator */}
+                        {!isValidShift && (
+                          <div style={{
+                            position: 'absolute',
+                            top: '2px',
+                            right: '2px',
+                            backgroundColor: '#f39c12',
+                            color: 'white',
+                            borderRadius: '50%',
+                            width: '16px',
+                            height: '16px',
+                            fontSize: '10px',
+                            display: 'flex',
+                            alignItems: 'center',
+                            justifyContent: 'center'
+                          }}
+                          title={`Shift Validierung: timeSlotId=${shift.timeSlotId}, dayOfWeek=${shift.dayOfWeek}`}
+                          >
+                            ⚠️
+                          </div>
+                        )}
+
                         <select
                           value={currentLevel}
                           onChange={(e) => {
@@ -360,10 +499,10 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
                           }}
                           style={{
                             padding: '8px 12px',
-                            border: `2px solid ${levelConfig?.color || '#ddd'}`,
+                            border: `2px solid ${!isValidShift ? '#f39c12' : (levelConfig?.color || '#ddd')}`,
                             borderRadius: '6px',
-                            backgroundColor: levelConfig?.bgColor || 'white',
-                            color: levelConfig?.color || '#333',
+                            backgroundColor: !isValidShift ? '#fff3cd' : (levelConfig?.bgColor || 'white'),
+                            color: !isValidShift ? '#856404' : (levelConfig?.color || '#333'),
                             fontWeight: 'bold',
                             minWidth: '140px',
                             cursor: 'pointer',
@@ -384,6 +523,23 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
                             </option>
                           ))}
                         </select>
+
+                        {/* Shift debug info */}
+                        <div style={{ 
+                          fontSize: '10px', 
+                          color: '#666', 
+                          marginTop: '4px',
+                          textAlign: 'left',
+                          fontFamily: 'monospace'
+                        }}>
+                          <div>Shift: {shift.id.substring(0, 6)}...</div>
+                          <div>Day: {shift.dayOfWeek}</div>
+                          {!isValidShift && (
+                            <div style={{ color: '#e74c3c', fontWeight: 'bold' }}>
+                              VALIDATION ERROR
+                            </div>
+                          )}
+                        </div>
                       </td>
                     );
                   })}
@@ -392,6 +548,27 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
             </tbody>
           </table>
         </div>
+
+        {/* Summary Statistics */}
+        <div style={{
+          backgroundColor: '#f8f9fa',
+          padding: '15px',
+          borderTop: '1px solid #dee2e6',
+          fontSize: '12px',
+          color: '#666'
+        }}>
+          <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}>
+            <div>
+              <strong>Zusammenfassung:</strong> {sortedTimeSlots.length} Zeitslots × {days.length} Tage = {sortedTimeSlots.length * days.length} mögliche Shifts
+            </div>
+            <div>
+              <strong>Aktive Verfügbarkeiten:</strong> {availabilities.filter(a => a.preferenceLevel !== 3).length}
+            </div>
+            <div>
+              <strong>Validierungsfehler:</strong> {validationErrors.length}
+            </div>
+          </div>
+        </div>
       </div>
     );
   };
@@ -406,14 +583,24 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
         return;
       }
 
-      const { days, shiftsByDay } = getTimetableData();
-      
-      // Filter availabilities to only include those with actual shifts
+      // Filter availabilities to only include those with actual shifts AND valid shiftIds
       const validAvailabilities = availabilities.filter(avail => {
+        // Check if this shiftId exists and is valid
+        if (!avail.shiftId) {
+          console.warn('⚠️ Überspringe ungültige Verfügbarkeit ohne Shift-ID:', avail);
+          return false;
+        }
+        
         // Check if this shiftId exists in the current plan
         return selectedPlan?.shifts?.some(shift => shift.id === avail.shiftId);
       });
 
+      console.log('💾 SPEICHERE VERFÜGBARKEITEN:', {
+        total: availabilities.length,
+        valid: validAvailabilities.length,
+        invalid: availabilities.length - validAvailabilities.length
+      });
+
       if (validAvailabilities.length === 0) {
         setError('Keine gültigen Verfügbarkeiten zum Speichern gefunden');
         return;
@@ -485,25 +672,63 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
 
       {/* Debug-Info */}
       <div style={{
-        backgroundColor: shiftsCount === 0 ? '#f8d7da' : '#d1ecf1',
-        border: `1px solid ${shiftsCount === 0 ? '#f5c6cb' : '#bee5eb'}`,
+        backgroundColor: !selectedPlan ? '#f8d7da' : (shiftsCount === 0 ? '#fff3cd' : '#d1ecf1'),
+        border: `1px solid ${!selectedPlan ? '#f5c6cb' : (shiftsCount === 0 ? '#ffeaa7' : '#bee5eb')}`,
         borderRadius: '6px',
         padding: '15px',
         marginBottom: '20px'
       }}>
         <h4 style={{ 
           margin: '0 0 10px 0', 
-          color: shiftsCount === 0 ? '#721c24' : '#0c5460' 
+          color: !selectedPlan ? '#721c24' : (shiftsCount === 0 ? '#856404' : '#0c5460') 
         }}>
-          {shiftsCount === 0 ? '❌ PROBLEM: Keine Shifts gefunden' : '✅ Plan-Daten geladen'}
+          {!selectedPlan ? '❌ KEIN PLAN AUSGEWÄHLT' : 
+           shiftsCount === 0 ? '⚠️ KEINE SHIFTS GEFUNDEN' : '✅ PLAN-DATEN GELADEN'}
         </h4>
         <div style={{ fontSize: '12px', fontFamily: 'monospace' }}>
           <div><strong>Ausgewählter Plan:</strong> {selectedPlan?.name || 'Keiner'}</div>
+          <div><strong>Plan ID:</strong> {selectedPlanId || 'Nicht gesetzt'}</div>
+          <div><strong>Geladene Pläne:</strong> {shiftPlans.length}</div>
           <div><strong>Einzigartige Shifts:</strong> {shiftsCount}</div>
-          <div><strong>Verwendete Tage:</strong> {days.length} ({days.map(d => d.name).join(', ')})</div>
-          <div><strong>Gesamte Shifts im Plan:</strong> {selectedPlan?.shifts?.length || 0}</div>
-          <div><strong>Methode:</strong> Direkte Shift-ID Zuordnung</div>
+          <div><strong>Geladene Verfügbarkeiten:</strong> {availabilities.length}</div>
+          {selectedPlan && (
+            <>
+              <div><strong>Verwendete Tage:</strong> {days.length} ({days.map(d => d.name).join(', ')})</div>
+              <div><strong>Gesamte Shifts im Plan:</strong> {selectedPlan.shifts?.length || 0}</div>
+            </>
+          )}
         </div>
+
+        {/* Show existing preferences */}
+        {availabilities.length > 0 && (
+          <div style={{ marginTop: '10px', paddingTop: '10px', borderTop: '1px solid #bee5eb' }}>
+            <strong>Vorhandene Präferenzen:</strong>
+            {availabilities.slice(0, 5).map(avail => {
+              // SICHERHEITSCHECK: Stelle sicher, dass shiftId existiert
+              if (!avail.shiftId) {
+                return (
+                  <div key={avail.id} style={{ fontSize: '11px', color: 'red' }}>
+                    • UNGÜLTIG: Keine Shift-ID
+                  </div>
+                );
+              }
+              
+              const shift = selectedPlan?.shifts?.find(s => s.id === avail.shiftId);
+              const shiftIdDisplay = avail.shiftId ? avail.shiftId.substring(0, 8) + '...' : 'KEINE ID';
+              
+              return (
+                <div key={avail.id} style={{ fontSize: '11px' }}>
+                  • Shift {shiftIdDisplay} (Day {shift?.dayOfWeek || '?'}): Level {avail.preferenceLevel}
+                </div>
+              );
+            })}
+            {availabilities.length > 5 && (
+              <div style={{ fontSize: '11px', fontStyle: 'italic' }}>
+                ... und {availabilities.length - 5} weitere
+              </div>
+            )}
+          </div>
+        )}
       </div>
 
       {/* Employee Info */}
@@ -588,7 +813,12 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
             </label>
             <select
               value={selectedPlanId}
-              onChange={(e) => setSelectedPlanId(e.target.value)}
+              onChange={(e) => {
+                const newPlanId = e.target.value;
+                console.log('🔄 PLAN WECHSELN ZU:', newPlanId);
+                setSelectedPlanId(newPlanId);
+                // Der useEffect wird automatisch ausgelöst
+              }}
               style={{
                 padding: '8px 12px',
                 border: '1px solid #ddd',
@@ -609,10 +839,25 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
             <div style={{ fontSize: '14px', color: '#666' }}>
               <div><strong>Plan:</strong> {selectedPlan.name}</div>
               <div><strong>Shifts:</strong> {selectedPlan.shifts?.length || 0}</div>
+              <div><strong>Zeitslots:</strong> {selectedPlan.timeSlots?.length || 0}</div>
               <div><strong>Status:</strong> {selectedPlan.status}</div>
             </div>
           )}
         </div>
+
+        {/* Debug Info für Plan Loading */}
+        {!selectedPlanId && shiftPlans.length > 0 && (
+          <div style={{
+            marginTop: '10px',
+            padding: '10px',
+            backgroundColor: '#fff3cd',
+            border: '1px solid #ffeaa7',
+            borderRadius: '4px',
+            fontSize: '12px'
+          }}>
+            ⚠️ Bitte wählen Sie einen Schichtplan aus
+          </div>
+        )}
       </div>
 
       {/* Availability Timetable */}
diff --git a/frontend/src/pages/Employees/components/EmployeeForm.tsx b/frontend/src/pages/Employees/components/EmployeeForm.tsx
index ac823dd..754917d 100644
--- a/frontend/src/pages/Employees/components/EmployeeForm.tsx
+++ b/frontend/src/pages/Employees/components/EmployeeForm.tsx
@@ -11,6 +11,9 @@ interface EmployeeFormProps {
   onCancel: () => void;
 }
 
+type EmployeeType = 'manager' | 'personell' | 'apprentice' | 'guest';
+type ContractType = 'small' | 'large' | 'flexible';
+
 const EmployeeForm: React.FC<EmployeeFormProps> = ({
   mode,
   employee,
@@ -20,13 +23,14 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
   const [formData, setFormData] = useState({
     firstname: '',
     lastname: '',
-    email: '', // Will be auto-generated and display only
+    email: '',
     password: '',
-    roles: ['user'] as string[], // Changed from single role to array
-    employeeType: 'trainee' as 'manager' | 'trainee' | 'experienced',
-    contractType: 'small' as 'small' | 'large',
+    roles: ['user'] as string[],
+    employeeType: 'personell' as EmployeeType,
+    contractType: 'small' as ContractType | undefined,
     canWorkAlone: false,
-    isActive: true
+    isActive: true,
+    isTrainee: false
   });
   const [passwordForm, setPasswordForm] = useState({
     newPassword: '',
@@ -62,12 +66,13 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
         firstname: employee.firstname,
         lastname: employee.lastname,
         email: employee.email,
-        password: '', // Password wird beim Bearbeiten nicht angezeigt
-        roles: employee.roles || ['user'], // Use roles array
+        password: '',
+        roles: employee.roles || ['user'],
         employeeType: employee.employeeType,
         contractType: employee.contractType,
         canWorkAlone: employee.canWorkAlone,
-        isActive: employee.isActive
+        isActive: employee.isActive,
+        isTrainee: employee.isTrainee || false
       });
     }
   }, [mode, employee]);
@@ -92,13 +97,11 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
   const handleRoleChange = (role: string, checked: boolean) => {
     setFormData(prev => {
       if (checked) {
-        // Add role if checked
         return {
           ...prev,
           roles: [...prev.roles, role]
         };
       } else {
-        // Remove role if unchecked
         return {
           ...prev,
           roles: prev.roles.filter(r => r !== role)
@@ -107,18 +110,36 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
     });
   };
 
-  const handleEmployeeTypeChange = (employeeType: 'manager' | 'trainee' | 'experienced') => {
-    // Manager and experienced can work alone, trainee cannot
-    const canWorkAlone = employeeType === 'manager' || employeeType === 'experienced';
+  const handleEmployeeTypeChange = (employeeType: EmployeeType) => {
+    // Determine if contract type should be shown and set default
+    const requiresContract = employeeType !== 'guest';
+    const defaultContractType = requiresContract ? 'small' as ContractType : undefined;
     
+    // Determine if can work alone based on employee type
+    const canWorkAlone = employeeType === 'manager' || 
+                        (employeeType === 'personell' && !formData.isTrainee);
+    
+    // Reset isTrainee if not personell
+    const isTrainee = employeeType === 'personell' ? formData.isTrainee : false;
+
     setFormData(prev => ({
       ...prev,
       employeeType,
-      canWorkAlone
+      contractType: defaultContractType,
+      canWorkAlone,
+      isTrainee
     }));
   };
 
-  const handleContractTypeChange = (contractType: 'small' | 'large') => {
+  const handleTraineeChange = (isTrainee: boolean) => {
+    setFormData(prev => ({
+      ...prev,
+      isTrainee,
+      canWorkAlone: prev.employeeType === 'personell' ? !isTrainee : prev.canWorkAlone
+    }));
+  };
+
+  const handleContractTypeChange = (contractType: ContractType) => {
     setFormData(prev => ({
       ...prev,
       contractType
@@ -136,25 +157,27 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
           firstname: formData.firstname.trim(),
           lastname: formData.lastname.trim(),
           password: formData.password,
-          roles: formData.roles, // Use roles array
+          roles: formData.roles,
           employeeType: formData.employeeType,
-          contractType: formData.contractType,
-          canWorkAlone: formData.canWorkAlone
+          contractType: formData.employeeType !== 'guest' ? formData.contractType : undefined,
+          canWorkAlone: formData.canWorkAlone,
+          isTrainee: formData.isTrainee
         };
         await employeeService.createEmployee(createData);
       } else if (employee) {
         const updateData: UpdateEmployeeRequest = {
           firstname: formData.firstname.trim(),
           lastname: formData.lastname.trim(),
-          roles: formData.roles, // Use roles array
+          roles: formData.roles,
           employeeType: formData.employeeType,
-          contractType: formData.contractType,
+          contractType: formData.employeeType !== 'guest' ? formData.contractType : undefined,
           canWorkAlone: formData.canWorkAlone,
           isActive: formData.isActive,
+          isTrainee: formData.isTrainee
         };
         await employeeService.updateEmployee(employee.id, updateData);
 
-        // If password change is requested and user is admin
+        // Password change logic remains the same
         if (showPasswordSection && passwordForm.newPassword && hasRole(['admin'])) {
           if (passwordForm.newPassword.length < 6) {
             throw new Error('Das neue Passwort muss mindestens 6 Zeichen lang sein');
@@ -163,9 +186,8 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
             throw new Error('Die Passwörter stimmen nicht überein');
           }
 
-          // Use the password change endpoint
           await employeeService.changePassword(employee.id, {
-            currentPassword: '', // Empty for admin reset - backend should handle this
+            currentPassword: '',
             newPassword: passwordForm.newPassword
           });
         }
@@ -189,9 +211,12 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
 
   const contractTypeOptions = [
     { value: 'small' as const, label: 'Kleiner Vertrag', description: '1 Schicht pro Woche' },
-    { value: 'large' as const, label: 'Großer Vertrag', description: '2 Schichten pro Woche' }
+    { value: 'large' as const, label: 'Großer Vertrag', description: '2 Schichten pro Woche' },
+    { value: 'flexible' as const, label: 'Flexibler Vertrag', description: 'Flexible Arbeitszeiten' }
   ];
 
+  const showContractType = formData.employeeType !== 'guest';
+
   return (
     <div style={{
       maxWidth: '700px',
@@ -330,8 +355,8 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
             )}
           </div>
 
-          {/* Vertragstyp (nur für Admins) */}
-          {hasRole(['admin']) && (
+          {/* Vertragstyp (nur für Admins und interne Mitarbeiter) */}
+          {hasRole(['admin']) && showContractType && (
             <div style={{
               padding: '20px',
               backgroundColor: '#e8f4fd',
@@ -470,6 +495,37 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
                 </div>
               ))}
             </div>
+
+            {/* FIXED: Trainee checkbox for personell type */}
+            {formData.employeeType === 'personell' && (
+              <div style={{ 
+                marginTop: '15px',
+                display: 'flex', 
+                alignItems: 'center', 
+                gap: '10px',
+                padding: '15px',
+                border: '1px solid #e0e0e0',
+                borderRadius: '6px',
+                backgroundColor: '#fff'
+              }}>
+                <input
+                  type="checkbox"
+                  name="isTrainee"
+                  id="isTrainee"
+                  checked={formData.isTrainee}
+                  onChange={(e) => handleTraineeChange(e.target.checked)}
+                  style={{ width: '18px', height: '18px' }}
+                />
+                <div>
+                  <label htmlFor="isTrainee" style={{ fontWeight: 'bold', color: '#2c3e50', display: 'block' }}>
+                    Als Neuling markieren
+                  </label>
+                  <div style={{ fontSize: '12px', color: '#7f8c8d' }}>
+                    Neulinge benötigen zusätzliche Betreuung und können nicht eigenständig arbeiten.
+                  </div>
+                </div>
+              </div>
+            )}
           </div>
 
           {/* Eigenständigkeit */}
@@ -496,11 +552,11 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
                 id="canWorkAlone"
                 checked={formData.canWorkAlone}
                 onChange={handleChange}
-                disabled={formData.employeeType === 'manager'}
+                disabled={formData.employeeType === 'manager' || (formData.employeeType === 'personell' && formData.isTrainee)}
                 style={{ 
                   width: '20px', 
                   height: '20px',
-                  opacity: formData.employeeType === 'manager' ? 0.5 : 1
+                  opacity: (formData.employeeType === 'manager' || (formData.employeeType === 'personell' && formData.isTrainee)) ? 0.5 : 1
                 }}
               />
               <div style={{ flex: 1 }}>
@@ -508,14 +564,16 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
                   fontWeight: 'bold', 
                   color: '#2c3e50', 
                   display: 'block',
-                  opacity: formData.employeeType === 'manager' ? 0.5 : 1
+                  opacity: (formData.employeeType === 'manager' || (formData.employeeType === 'personell' && formData.isTrainee)) ? 0.5 : 1
                 }}>
                   Als ausreichend eigenständig markieren
-                  {formData.employeeType === 'manager' && ' (Automatisch für Chefs)'}
+                  {(formData.employeeType === 'manager' || (formData.employeeType === 'personell' && formData.isTrainee)) && ' (Automatisch festgelegt)'}
                 </label>
                 <div style={{ fontSize: '14px', color: '#7f8c8d' }}>
                   {formData.employeeType === 'manager' 
                     ? 'Chefs sind automatisch als eigenständig markiert.'
+                    : formData.employeeType === 'personell' && formData.isTrainee
+                    ? 'Auszubildende können nicht als eigenständig markiert werden.'
                     : 'Dieser Mitarbeiter kann komplexe Aufgaben eigenständig lösen und benötigt keine ständige Betreuung.'
                   }
                 </div>
@@ -527,7 +585,7 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
                 borderRadius: '15px',
                 fontSize: '12px',
                 fontWeight: 'bold',
-                opacity: formData.employeeType === 'manager' ? 0.7 : 1
+                opacity: (formData.employeeType === 'manager' || (formData.employeeType === 'personell' && formData.isTrainee)) ? 0.7 : 1
               }}>
                 {formData.canWorkAlone ? 'EIGENSTÄNDIG' : 'BETREUUNG'}
               </div>
@@ -632,7 +690,7 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
             </div>
           )}
 
-          {/* Systemrollen (nur für Admins) */}
+          {/* Systemrollen (nur für Admins) - AKTUALISIERT FÜR MEHRFACHE ROLLEN */}
           {hasRole(['admin']) && (
             <div style={{
               padding: '20px',
@@ -714,6 +772,7 @@ const EmployeeForm: React.FC<EmployeeFormProps> = ({
               </div>
             </div>
           )}
+          
         </div>
 
         {/* Buttons */}
diff --git a/frontend/src/pages/Employees/components/EmployeeList.tsx b/frontend/src/pages/Employees/components/EmployeeList.tsx
index 9555b3a..931ef40 100644
--- a/frontend/src/pages/Employees/components/EmployeeList.tsx
+++ b/frontend/src/pages/Employees/components/EmployeeList.tsx
@@ -1,3 +1,4 @@
+// EmployeeList.tsx
 import React, { useState } from 'react';
 import { ROLE_CONFIG, EMPLOYEE_TYPE_CONFIG } from '../../../models/defaults/employeeDefaults';
 import { Employee } from '../../../models/Employee';
@@ -13,6 +14,9 @@ interface EmployeeListProps {
 type SortField = 'name' | 'employeeType' | 'canWorkAlone' | 'role' | 'lastLogin';
 type SortDirection = 'asc' | 'desc';
 
+// FIXED: Use the actual employee types from the Employee interface
+type EmployeeType = 'manager' | 'personell' | 'apprentice' | 'guest';
+
 const EmployeeList: React.FC<EmployeeListProps> = ({
   employees,
   onEdit,
@@ -122,18 +126,18 @@ const EmployeeList: React.FC<EmployeeListProps> = ({
     return false;
   };
 
-  // Using shared configuration for consistent styling
-  type EmployeeType = 'manager' | 'trainee' | 'experienced';
-
-  const getEmployeeTypeBadge = (type: EmployeeType) => {
+  const getEmployeeTypeBadge = (type: EmployeeType, isTrainee: boolean = false) => {
     const config = EMPLOYEE_TYPE_CONFIG[type];
 
+    // FIXED: Updated color mapping for actual employee types
     const bgColor =
       type === 'manager'
-        ? '#fadbd8'
-        : type === 'trainee'
-        ? '#d5f4e6'
-        : '#d6eaf8'; // experienced
+        ? '#fadbd8' // light red
+        : type === 'personell'
+        ? isTrainee ? '#d5f4e6' : '#d6eaf8' // light green for trainee, light blue for experienced
+        : type === 'apprentice'
+        ? '#e8d7f7' // light purple for apprentice
+        : '#f8f9fa'; // light gray for guest
 
     return { text: config.label, color: config.color, bgColor };
   };
@@ -296,7 +300,8 @@ const EmployeeList: React.FC<EmployeeListProps> = ({
         </div>
 
         {sortedEmployees.map(employee => {
-          const employeeType = getEmployeeTypeBadge(employee.employeeType);
+          // FIXED: Type assertion to ensure type safety
+          const employeeType = getEmployeeTypeBadge(employee.employeeType as EmployeeType, employee.isTrainee);
           const independence = getIndependenceBadge(employee.canWorkAlone);
           const roleInfo = getRoleBadge(employee.roles);
           const status = getStatusBadge(employee.isActive);
@@ -541,19 +546,30 @@ const EmployeeList: React.FC<EmployeeListProps> = ({
               borderRadius: '12px',
               fontSize: '11px',
               fontWeight: 'bold'
-            }}>👴 ERFAHREN</span>
-            <span style={{ fontSize: '12px', color: '#666' }}>Langjährige Erfahrung</span>
+            }}>👨‍🏭 PERSONAL</span>
+            <span style={{ fontSize: '12px', color: '#666' }}>Reguläre Mitarbeiter</span>
           </div>
           <div style={{ display: 'flex', alignItems: 'center', gap: '5px' }}>
             <span style={{
-              backgroundColor: '#d5f4e6',
-              color: '#27ae60',
+              backgroundColor: '#e8d7f7',
+              color: '#9b59b6',
               padding: '4px 8px',
               borderRadius: '12px',
               fontSize: '11px',
               fontWeight: 'bold'
-            }}>👶 NEULING</span>
-            <span style={{ fontSize: '12px', color: '#666' }}>Benötigt Einarbeitung</span>
+            }}>👨‍🎓 AUSZUBILDENDER</span>
+            <span style={{ fontSize: '12px', color: '#666' }}>Auszubildende</span>
+          </div>
+          <div style={{ display: 'flex', alignItems: 'center', gap: '5px' }}>
+            <span style={{
+              backgroundColor: '#f8f9fa',
+              color: '#95a5a6',
+              padding: '4px 8px',
+              borderRadius: '12px',
+              fontSize: '11px',
+              fontWeight: 'bold'
+            }}>👤 GAST</span>
+            <span style={{ fontSize: '12px', color: '#666' }}>Externe Mitarbeiter</span>
           </div>
         </div>
       </div>
diff --git a/frontend/src/pages/ShiftPlans/ShiftPlanView.tsx b/frontend/src/pages/ShiftPlans/ShiftPlanView.tsx
index 30cb950..59211d1 100644
--- a/frontend/src/pages/ShiftPlans/ShiftPlanView.tsx
+++ b/frontend/src/pages/ShiftPlans/ShiftPlanView.tsx
@@ -16,14 +16,27 @@ interface ExtendedTimeSlot extends TimeSlot {
   displayName?: string;
 }
 
+interface ExtendedShift {
+  id: string;
+  planId: string;
+  timeSlotId: string;
+  dayOfWeek: number;
+  requiredEmployees: number;
+  color?: string;
+  timeSlotName?: string;
+  startTime?: string;
+  endTime?: string;
+  displayName?: string;
+}
+
 const weekdays = [
-  { id: 1, name: 'Mo' },
-  { id: 2, name: 'Di' },
-  { id: 3, name: 'Mi' },
-  { id: 4, name: 'Do' },
-  { id: 5, name: 'Fr' },
-  { id: 6, name: 'Sa' },
-  { id: 7, name: 'So' }
+  { id: 1, name: 'Montag' },
+  { id: 2, name: 'Dienstag' },
+  { id: 3, name: 'Mittwoch' },
+  { id: 4, name: 'Donnerstag' },
+  { id: 5, name: 'Freitag' },
+  { id: 6, name: 'Samstag' },
+  { id: 7, name: 'Sonntag' }
 ];
 
 const ShiftPlanView: React.FC = () => {
@@ -35,14 +48,13 @@ const ShiftPlanView: React.FC = () => {
   const [shiftPlan, setShiftPlan] = useState<ShiftPlan | null>(null);
   const [employees, setEmployees] = useState<Employee[]>([]);
   const [availabilities, setAvailabilities] = useState<EmployeeAvailability[]>([]);
-  const [assignmentResult, setAssignmentResult] = useState<AssignmentResult | null>(null); // Add this line
+  const [assignmentResult, setAssignmentResult] = useState<AssignmentResult | null>(null);
   const [loading, setLoading] = useState(true);
   const [publishing, setPublishing] = useState(false);
   const [scheduledShifts, setScheduledShifts] = useState<ScheduledShift[]>([]);
   const [showAssignmentPreview, setShowAssignmentPreview] = useState(false);
   const [recreating, setRecreating] = useState(false);
 
-
   useEffect(() => {
     loadShiftPlanData();
     
@@ -76,31 +88,133 @@ const ShiftPlanView: React.FC = () => {
     };
   }, []);
 
+  // Add this useEffect to debug state changes
   useEffect(() => {
-    if (assignmentResult) {
-      console.log("🔄 assignmentResult UPDATED:", {
-        success: assignmentResult.success,
-        assignmentsCount: Object.keys(assignmentResult.assignments).length,
-        assignmentKeys: Object.keys(assignmentResult.assignments).slice(0, 5), // First 5 keys
-        violations: assignmentResult.violations.length
-      });
-      
-      // Log all assignments with their keys
-      Object.entries(assignmentResult.assignments).forEach(([key, empIds]) => {
-        console.log(`   🗂️ Assignment Key: ${key}`);
-        console.log(`      Employees: ${empIds.join(', ')}`);
-        
-        // Try to identify what this key represents
-        const isUuid = key.length === 36; // UUID format
-        console.log(`      Type: ${isUuid ? 'UUID (likely scheduled shift)' : 'Pattern (likely shift pattern)'}`);
-      });
-    }
-  }, [assignmentResult]);
+    console.log('🔍 STATE DEBUG - showAssignmentPreview:', showAssignmentPreview);
+    console.log('🔍 STATE DEBUG - assignmentResult:', assignmentResult ? 'EXISTS' : 'NULL');
+    console.log('🔍 STATE DEBUG - publishing:', publishing);
+  }, [showAssignmentPreview, assignmentResult, publishing]);
 
-  useEffect(() => {
-    (window as any).debugRenderLogic = debugRenderLogic;
-    return () => { (window as any).debugRenderLogic = undefined; };
-  }, [shiftPlan, scheduledShifts]);
+  // Create a data structure that maps days to their shifts with time slot info - SAME AS AVAILABILITYMANAGER
+  const getTimetableData = () => {
+    if (!shiftPlan || !shiftPlan.shifts || !shiftPlan.timeSlots) {
+      return { days: [], shiftsByDay: {}, allTimeSlots: [] };
+    }
+
+    // Create a map for quick time slot lookups
+    const timeSlotMap = new Map(shiftPlan.timeSlots.map(ts => [ts.id, ts]));
+
+    // Group shifts by day and enhance with time slot info - SAME LOGIC AS AVAILABILITYMANAGER
+    const shiftsByDay = shiftPlan.shifts.reduce((acc, shift) => {
+      if (!acc[shift.dayOfWeek]) {
+        acc[shift.dayOfWeek] = [];
+      }
+      
+      const timeSlot = timeSlotMap.get(shift.timeSlotId);
+      const enhancedShift: ExtendedShift = {
+        ...shift,
+        timeSlotName: timeSlot?.name,
+        startTime: timeSlot?.startTime,
+        endTime: timeSlot?.endTime,
+        displayName: timeSlot ? `${timeSlot.name} (${formatTime(timeSlot.startTime)}-${formatTime(timeSlot.endTime)})` : shift.id
+      };
+      
+      acc[shift.dayOfWeek].push(enhancedShift);
+      return acc;
+    }, {} as Record<number, ExtendedShift[]>);
+
+    // Sort shifts within each day by start time - SAME LOGIC AS AVAILABILITYMANAGER
+    Object.keys(shiftsByDay).forEach(day => {
+      shiftsByDay[parseInt(day)].sort((a, b) => {
+        const timeA = a.startTime || '';
+        const timeB = b.startTime || '';
+        return timeA.localeCompare(timeB);
+      });
+    });
+
+    // Get unique days that have shifts - SAME LOGIC AS AVAILABILITYMANAGER
+    const days = Array.from(new Set(shiftPlan.shifts.map(shift => shift.dayOfWeek)))
+      .sort()
+      .map(dayId => {
+        return weekdays.find(day => day.id === dayId) || { id: dayId, name: `Tag ${dayId}` };
+      });
+
+    // Get all unique time slots (rows) by collecting from all shifts - SAME LOGIC AS AVAILABILITYMANAGER
+    const allTimeSlotsMap = new Map();
+    days.forEach(day => {
+      shiftsByDay[day.id]?.forEach(shift => {
+        const timeSlot = timeSlotMap.get(shift.timeSlotId);
+        if (timeSlot && !allTimeSlotsMap.has(timeSlot.id)) {
+          allTimeSlotsMap.set(timeSlot.id, {
+            ...timeSlot,
+            shiftsByDay: {} // Initialize empty object to store shifts by day
+          });
+        }
+      });
+    });
+
+    // Populate shifts for each time slot by day - SAME LOGIC AS AVAILABILITYMANAGER
+    days.forEach(day => {
+      shiftsByDay[day.id]?.forEach(shift => {
+        const timeSlot = allTimeSlotsMap.get(shift.timeSlotId);
+        if (timeSlot) {
+          timeSlot.shiftsByDay[day.id] = shift;
+        }
+      });
+    });
+
+    // Convert to array and sort by start time - SAME LOGIC AS AVAILABILITYMANAGER
+    const allTimeSlots = Array.from(allTimeSlotsMap.values()).sort((a, b) => {
+      return (a.startTime || '').localeCompare(b.startTime || '');
+    });
+
+    return { days, shiftsByDay, allTimeSlots };
+  };
+
+  // VALIDATION FUNCTION - Check if shifts are correctly placed (like in AvailabilityManager)
+  const validateTimetableStructure = () => {
+    if (!shiftPlan || !shiftPlan.shifts || !shiftPlan.timeSlots) {
+      return { isValid: false, errors: ['No shift plan data available'] };
+    }
+
+    const validationErrors: string[] = [];
+    
+    // Check for missing time slots - SAME VALIDATION AS AVAILABILITYMANAGER
+    const usedTimeSlotIds = new Set(shiftPlan.shifts.map(s => s.timeSlotId));
+    const availableTimeSlotIds = new Set(shiftPlan.timeSlots.map(ts => ts.id));
+    
+    usedTimeSlotIds.forEach(timeSlotId => {
+      if (!availableTimeSlotIds.has(timeSlotId)) {
+        validationErrors.push(`Zeitslot ${timeSlotId} wird verwendet, existiert aber nicht in timeSlots`);
+      }
+    });
+
+    // Check for shifts with invalid day numbers - SAME VALIDATION AS AVAILABILITYMANAGER
+    shiftPlan.shifts.forEach(shift => {
+      if (shift.dayOfWeek < 1 || shift.dayOfWeek > 7) {
+        validationErrors.push(`Shift ${shift.id} hat ungültigen Wochentag: ${shift.dayOfWeek}`);
+      }
+
+      // Check if shift timeSlotId exists in timeSlots
+      const timeSlotExists = shiftPlan.timeSlots.some(ts => ts.id === shift.timeSlotId);
+      if (!timeSlotExists) {
+        validationErrors.push(`Shift ${shift.id} verweist auf nicht existierenden Zeitslot: ${shift.timeSlotId}`);
+      }
+    });
+
+    // Check for scheduled shifts consistency
+    scheduledShifts.forEach(scheduledShift => {
+      const timeSlotExists = shiftPlan.timeSlots.some(ts => ts.id === scheduledShift.timeSlotId);
+      if (!timeSlotExists) {
+        validationErrors.push(`Scheduled Shift ${scheduledShift.id} verweist auf nicht existierenden Zeitslot: ${scheduledShift.timeSlotId}`);
+      }
+    });
+
+    return {
+      isValid: validationErrors.length === 0,
+      errors: validationErrors
+    };
+  };
 
   const loadShiftPlanData = async () => {
     if (!id) return;
@@ -132,7 +246,9 @@ const ShiftPlanView: React.FC = () => {
 
       setScheduledShifts(shiftsData);
 
-      // Load availabilities
+      // Load availabilities - USING THE SAME LOGIC AS AVAILABILITYMANAGER
+      console.log('🔄 LADE VERFÜGBARKEITEN FÜR PLAN:', id);
+      
       const availabilityPromises = employeesData
         .filter(emp => emp.isActive)
         .map(emp => employeeService.getAvailabilities(emp.id));
@@ -140,12 +256,21 @@ const ShiftPlanView: React.FC = () => {
       const allAvailabilities = await Promise.all(availabilityPromises);
       const flattenedAvailabilities = allAvailabilities.flat();
       
+      // Filter to only include availabilities for the current plan - SAME LOGIC AS AVAILABILITYMANAGER
       const planAvailabilities = flattenedAvailabilities.filter(
         availability => availability.planId === id
       );
       
+      console.log('✅ VERFÜGBARKEITEN FÜR DIESEN PLAN:', planAvailabilities.length);
+      
       setAvailabilities(planAvailabilities);
 
+      // Run validation
+      const validation = validateTimetableStructure();
+      if (!validation.isValid) {
+        console.warn('⚠️ TIMETABLE VALIDATION ERRORS:', validation.errors);
+      }
+
     } catch (error) {
       console.error('Error loading shift plan data:', error);
       showNotification({
@@ -222,143 +347,6 @@ const ShiftPlanView: React.FC = () => {
     }
   };
 
-  const debugRenderLogic = () => {
-    if (!shiftPlan) return;
-    
-    console.log('🔍 RENDER LOGIC DEBUG:');
-    console.log('=====================');
-    
-    const { days, allTimeSlots, timeSlotsByDay } = getTimetableData();
-    
-    console.log('📊 TABLE STRUCTURE:');
-    console.log('- Days in table:', days.length);
-    console.log('- TimeSlots in table:', allTimeSlots.length);
-    console.log('- Days with data:', Object.keys(timeSlotsByDay).length);
-    
-    // Zeige die tatsächliche Struktur der Tabelle
-    console.log('\n📅 ACTUAL TABLE DAYS:');
-    days.forEach(day => {
-      const slotsForDay = timeSlotsByDay[day.id] || [];
-      console.log(`- ${day.name}: ${slotsForDay.length} time slots`);
-    });
-    
-    console.log('\n⏰ ACTUAL TIME SLOTS:');
-    allTimeSlots.forEach(slot => {
-      console.log(`- ${slot.name} (${slot.startTime}-${slot.endTime})`);
-    });
-    
-    // Prüfe wie viele Scheduled Shifts tatsächlich gerendert werden
-    console.log('\n🔍 SCHEDULED SHIFTS RENDER ANALYSIS:');
-    
-    let totalRenderedShifts = 0;
-    let shiftsWithAssignments = 0;
-    
-    days.forEach(day => {
-      const slotsForDay = timeSlotsByDay[day.id] || [];
-      slotsForDay.forEach(timeSlot => {
-        totalRenderedShifts++;
-        
-        // Finde den entsprechenden Scheduled Shift
-        const scheduledShift = scheduledShifts.find(scheduled => {
-          const scheduledDayOfWeek = getDayOfWeek(scheduled.date);
-          return scheduledDayOfWeek === day.id && 
-                scheduled.timeSlotId === timeSlot.id;
-        });
-        
-        if (scheduledShift && scheduledShift.assignedEmployees && scheduledShift.assignedEmployees.length > 0) {
-          shiftsWithAssignments++;
-        }
-      });
-    });
-    
-    console.log(`- Total shifts in table: ${totalRenderedShifts}`);
-    console.log(`- Shifts with assignments: ${shiftsWithAssignments}`);
-    console.log(`- Total scheduled shifts: ${scheduledShifts.length}`);
-    console.log(`- Coverage: ${Math.round((totalRenderedShifts / scheduledShifts.length) * 100)}%`);
-    
-    // Problem-Analyse
-    if (totalRenderedShifts < scheduledShifts.length) {
-      console.log('\n🚨 PROBLEM: Table is not showing all scheduled shifts!');
-      console.log('💡 The table structure (days × timeSlots) is smaller than actual scheduled shifts');
-      
-      // Zeige die fehlenden Shifts
-      const missingShifts = scheduledShifts.filter(scheduled => {
-        const dayOfWeek = getDayOfWeek(scheduled.date);
-        const timeSlotExists = allTimeSlots.some(ts => ts.id === scheduled.timeSlotId);
-        const dayExists = days.some(day => day.id === dayOfWeek);
-        
-        return !(timeSlotExists && dayExists);
-      });
-      
-      if (missingShifts.length > 0) {
-        console.log(`❌ ${missingShifts.length} shifts cannot be rendered in table:`);
-        missingShifts.slice(0, 5).forEach(shift => {
-          const dayOfWeek = getDayOfWeek(shift.date);
-          const timeSlot = shiftPlan.timeSlots?.find(ts => ts.id === shift.timeSlotId);
-          console.log(`   - ${shift.date} (Day ${dayOfWeek}): ${timeSlot?.name || 'Unknown'} - ${shift.assignedEmployees?.length || 0} assignments`);
-        });
-      }
-    }
-  };
-
-  // Extract plan-specific shifts using the same logic as AvailabilityManager
-  const getTimetableData = () => {
-    if (!shiftPlan || !shiftPlan.shifts || !shiftPlan.timeSlots) {
-      return { days: [], timeSlotsByDay: {}, allTimeSlots: [] };
-    }
-
-    // Group shifts by day
-    const shiftsByDay = shiftPlan.shifts.reduce((acc, shift) => {
-      if (!acc[shift.dayOfWeek]) {
-        acc[shift.dayOfWeek] = [];
-      }
-      acc[shift.dayOfWeek].push(shift);
-      return acc;
-    }, {} as Record<number, typeof shiftPlan.shifts>);
-
-    // Get unique days that have shifts
-    const days = Array.from(new Set(shiftPlan.shifts.map(shift => shift.dayOfWeek)))
-      .sort()
-      .map(dayId => {
-        return weekdays.find(day => day.id === dayId) || { id: dayId, name: `Tag ${dayId}` };
-      });
-
-    // For each day, get the time slots that actually have shifts
-    const timeSlotsByDay: Record<number, ExtendedTimeSlot[]> = {};
-    
-    days.forEach(day => {
-      const shiftsForDay = shiftsByDay[day.id] || [];
-      const timeSlotIdsForDay = new Set(shiftsForDay.map(shift => shift.timeSlotId));
-      
-      timeSlotsByDay[day.id] = shiftPlan.timeSlots
-        .filter(timeSlot => timeSlotIdsForDay.has(timeSlot.id))
-        .map(timeSlot => ({
-          ...timeSlot,
-          displayName: `${timeSlot.name} (${formatTime(timeSlot.startTime)}-${formatTime(timeSlot.endTime)})`
-        }))
-        .sort((a, b) => a.startTime.localeCompare(b.startTime));
-    });
-
-    // Get all unique time slots across all days for row headers
-    const allTimeSlotIds = new Set<string>();
-    days.forEach(day => {
-      timeSlotsByDay[day.id]?.forEach(timeSlot => {
-        allTimeSlotIds.add(timeSlot.id);
-      });
-    });
-
-    const allTimeSlots = Array.from(allTimeSlotIds)
-      .map(timeSlotId => shiftPlan.timeSlots.find(ts => ts.id === timeSlotId))
-      .filter(Boolean)
-      .map(timeSlot => ({
-        ...timeSlot!,
-        displayName: `${timeSlot!.name} (${formatTime(timeSlot!.startTime)}-${formatTime(timeSlot!.endTime)})`
-      }))
-      .sort((a, b) => a.startTime.localeCompare(b.startTime));
-
-    return { days, timeSlotsByDay, allTimeSlots };
-  };
-
   const getDayOfWeek = (dateString: string): number => {
     const date = new Date(dateString);
     return date.getDay() === 0 ? 7 : date.getDay();
@@ -369,20 +357,31 @@ const ShiftPlanView: React.FC = () => {
 
     try {
       setPublishing(true);
+      setAssignmentResult(null); // Reset previous results
+      setShowAssignmentPreview(false); // Reset preview
+      
+      console.log('🔄 STARTING ASSIGNMENT PREVIEW...');
       
       // FORCE COMPLETE REFRESH - don't rely on cached state
       const [refreshedEmployees, refreshedAvailabilities] = await Promise.all([
-        // Reload employees fresh
         employeeService.getEmployees().then(emps => emps.filter(emp => emp.isActive)),
-        // Reload availabilities fresh
         refreshAllAvailabilities()
       ]);
 
       console.log('🔄 USING FRESH DATA:');
       console.log('- Employees:', refreshedEmployees.length);
       console.log('- Availabilities:', refreshedAvailabilities.length);
+      console.log('- Shift Patterns:', shiftPlan.shifts?.length || 0);
+      console.log('- Scheduled Shifts:', scheduledShifts.length);
+
+      // DEBUG: Show shift pattern IDs
+      if (shiftPlan.shifts) {
+        console.log('📋 SHIFT PATTERN IDs:');
+        shiftPlan.shifts.forEach((shift, index) => {
+          console.log(`   ${index + 1}. ${shift.id} (Day ${shift.dayOfWeek}, TimeSlot ${shift.timeSlotId})`);
+        });
+      }
 
-      // ADD THIS: Define constraints object
       const constraints = {
         enforceNoTraineeAlone: true,
         enforceExperiencedWithChef: true,
@@ -390,6 +389,8 @@ const ShiftPlanView: React.FC = () => {
         targetEmployeesPerShift: 2
       };
 
+      console.log('🧠 Calling shift assignment service...');
+      
       // Use the freshly loaded data, not the state
       const result = await shiftAssignmentService.assignShifts(
         shiftPlan,
@@ -398,7 +399,6 @@ const ShiftPlanView: React.FC = () => {
         constraints
       );
 
-      // COMPREHENSIVE DEBUGGING
       console.log("🎯 RAW ASSIGNMENT RESULT FROM API:", {
         success: result.success,
         assignmentsCount: Object.keys(result.assignments).length,
@@ -407,31 +407,31 @@ const ShiftPlanView: React.FC = () => {
         resolutionReport: result.resolutionReport?.length || 0
       });
 
-      // Log the actual assignments with more context
+      // Log assignments with shift pattern context
+      console.log('🔍 ASSIGNMENTS BY SHIFT PATTERN:');
       Object.entries(result.assignments).forEach(([shiftId, empIds]) => {
-        console.log(`   📅 Assignment Key: ${shiftId}`);
-        console.log(`      Employees: ${empIds.join(', ')}`);
+        const shiftPattern = shiftPlan.shifts?.find(s => s.id === shiftId);
         
-        // Try to identify what type of ID this is
-        const isUuid = shiftId.length === 36; // UUID format
-        console.log(`      Type: ${isUuid ? 'UUID (likely scheduled shift)' : 'Pattern (likely shift pattern)'}`);
-        
-        // If it's a UUID, check if it matches any scheduled shift
-        if (isUuid) {
-          const matchingScheduledShift = scheduledShifts.find(s => s.id === shiftId);
-          if (matchingScheduledShift) {
-            console.log(`      ✅ Matches scheduled shift: ${matchingScheduledShift.date} - TimeSlot: ${matchingScheduledShift.timeSlotId}`);
-          } else {
-            console.log(`      ❌ No matching scheduled shift found for UUID`);
-          }
+        if (shiftPattern) {
+          console.log(`   ✅ Shift Pattern: ${shiftId}`);
+          console.log(`      - Day: ${shiftPattern.dayOfWeek}, TimeSlot: ${shiftPattern.timeSlotId}`);
+          console.log(`      - Employees: ${empIds.join(', ')}`);
+        } else {
+          console.log(`   ❌ UNKNOWN ID: ${shiftId}`);
+          console.log(`      - Employees: ${empIds.join(', ')}`);
+          console.log(`      - This ID does not match any shift pattern!`);
         }
       });
 
+      // CRITICAL: Update state and show preview
+      console.log('🔄 Setting assignment result and showing preview...');
       setAssignmentResult(result);
       setShowAssignmentPreview(true);
+      
+      console.log('✅ Assignment preview ready, modal should be visible');
 
     } catch (error) {
-      console.error('Error during assignment:', error);
+      console.error('❌ Error during assignment:', error);
       showNotification({
         type: 'error',
         title: 'Fehler',
@@ -458,13 +458,13 @@ const ShiftPlanView: React.FC = () => {
       }
 
       console.log(`📊 Found ${updatedShifts.length} scheduled shifts to update`);
+      console.log('🎯 Assignment keys from algorithm:', Object.keys(assignmentResult.assignments));
 
       const updatePromises = updatedShifts.map(async (scheduledShift) => {
-        // ✅ FIX: Map scheduled shift to shift pattern to find assignments
         const dayOfWeek = getDayOfWeek(scheduledShift.date);
         
         // Find the corresponding shift pattern for this day and time slot
-        const shiftPattern = shiftPlan.shifts?.find(shift => 
+        const shiftPattern = shiftPlan?.shifts?.find(shift => 
           shift.dayOfWeek === dayOfWeek && 
           shift.timeSlotId === scheduledShift.timeSlotId
         );
@@ -472,9 +472,13 @@ const ShiftPlanView: React.FC = () => {
         let assignedEmployees: string[] = [];
         
         if (shiftPattern) {
-          // Look for assignments using the shift pattern ID (what scheduler uses)
           assignedEmployees = assignmentResult.assignments[shiftPattern.id] || [];
           console.log(`📝 Updating scheduled shift ${scheduledShift.id} (Day ${dayOfWeek}, TimeSlot ${scheduledShift.timeSlotId}) with`, assignedEmployees, 'employees');
+          
+          if (assignedEmployees.length === 0) {
+            console.warn(`⚠️ No assignments found for shift pattern ${shiftPattern.id}`);
+            console.log('🔍 Available assignment keys:', Object.keys(assignmentResult.assignments));
+          }
         } else {
           console.warn(`⚠️ No shift pattern found for scheduled shift ${scheduledShift.id} (Day ${dayOfWeek}, TimeSlot ${scheduledShift.timeSlotId})`);
         }
@@ -509,14 +513,17 @@ const ShiftPlanView: React.FC = () => {
       setShiftPlan(reloadedPlan);
       setScheduledShifts(reloadedShifts);
 
+      setShowAssignmentPreview(false);
+      setAssignmentResult(null);
+
+      console.log('✅ Publishing completed, modal closed');
+
       showNotification({
         type: 'success',
         title: 'Erfolg',
         message: 'Schichtplan wurde erfolgreich veröffentlicht!'
       });
 
-      setShowAssignmentPreview(false);
-
     } catch (error) {
       console.error('❌ Error publishing shift plan:', error);
       
@@ -576,37 +583,37 @@ const ShiftPlanView: React.FC = () => {
     }
   };
 
-  const validateSchedulingData = (): boolean => {
-    console.log('🔍 Validating scheduling data...');
+  const debugShiftMatching = () => {
+    if (!shiftPlan || !scheduledShifts.length) return;
     
-    const totalEmployees = employees.length;
-    const employeesWithAvailabilities = new Set(
-      availabilities.map(avail => avail.employeeId)
-    ).size;
+    console.log('🔍 DEBUG: Shift Pattern to Scheduled Shift Matching');
+    console.log('==================================================');
     
-    const availabilityStatus = {
-      totalEmployees,
-      employeesWithAvailabilities,
-      coverage: Math.round((employeesWithAvailabilities / totalEmployees) * 100)
-    };
-    
-    console.log('📊 Availability Coverage:', availabilityStatus);
-    
-    // Check if we have ALL employee availabilities
-    if (employeesWithAvailabilities < totalEmployees) {
-      const missingEmployees = employees.filter(emp => 
-        !availabilities.some(avail => avail.employeeId === emp.id)
-      );
+    shiftPlan.shifts?.forEach(shiftPattern => {
+      const matchingScheduledShifts = scheduledShifts.filter(scheduled => {
+        const dayOfWeek = getDayOfWeek(scheduled.date);
+        return dayOfWeek === shiftPattern.dayOfWeek && 
+              scheduled.timeSlotId === shiftPattern.timeSlotId;
+      });
       
-      console.warn('⚠️ Missing availabilities for employees:', 
-        missingEmployees.map(emp => emp.email));
+      console.log(`📅 Shift Pattern: ${shiftPattern.id}`);
+      console.log(`   - Day: ${shiftPattern.dayOfWeek}, TimeSlot: ${shiftPattern.timeSlotId}`);
+      console.log(`   - Matching scheduled shifts: ${matchingScheduledShifts.length}`);
       
-      return false;
-    }
-    
-    return true;
+      if (assignmentResult) {
+        const assignments = assignmentResult.assignments[shiftPattern.id] || [];
+        console.log(`   - Assignments: ${assignments.length} employees`);
+      }
+    });
   };
 
+  // Rufe die Debug-Funktion auf, wenn Assignment-Ergebnisse geladen werden
+  useEffect(() => {
+    if (assignmentResult && shiftPlan) {
+      debugShiftMatching();
+    }
+  }, [assignmentResult, shiftPlan]);
+
   const canPublish = () => {
     if (!shiftPlan || shiftPlan.status === 'published') return false;
     
@@ -660,32 +667,33 @@ const ShiftPlanView: React.FC = () => {
   const getAssignmentsForScheduledShift = (scheduledShift: ScheduledShift): string[] => {
     if (!assignmentResult) return [];
     
-    // First try direct match with scheduled shift ID
-    if (assignmentResult.assignments[scheduledShift.id]) {
-      return assignmentResult.assignments[scheduledShift.id];
-    }
-    
-    // If no direct match, try to find by day and timeSlot pattern
     const dayOfWeek = getDayOfWeek(scheduledShift.date);
+    
+    // Find the corresponding shift pattern for this day and time slot
     const shiftPattern = shiftPlan?.shifts?.find(shift => 
       shift.dayOfWeek === dayOfWeek && 
       shift.timeSlotId === scheduledShift.timeSlotId
     );
     
     if (shiftPattern && assignmentResult.assignments[shiftPattern.id]) {
+      console.log(`✅ Found assignments for shift pattern ${shiftPattern.id}:`, assignmentResult.assignments[shiftPattern.id]);
       return assignmentResult.assignments[shiftPattern.id];
     }
     
+    // Fallback: Check if there's a direct match with scheduled shift ID (unlikely)
+    if (assignmentResult.assignments[scheduledShift.id]) {
+      console.log(`⚠️ Using direct scheduled shift assignment for ${scheduledShift.id}`);
+      return assignmentResult.assignments[scheduledShift.id];
+    }
+    
+    console.warn(`❌ No assignments found for scheduled shift ${scheduledShift.id} (Day ${dayOfWeek}, TimeSlot ${scheduledShift.timeSlotId})`);
     return [];
   };
 
   // Render timetable using the same structure as AvailabilityManager
   const renderTimetable = () => {
-    const { days, allTimeSlots, timeSlotsByDay } = getTimetableData();
-    if (!shiftPlan?.id) {
-      console.warn("Shift plan ID is missing");
-      return null;
-    }
+    const { days, allTimeSlots } = getTimetableData();
+    const validation = validateTimetableStructure();
 
     if (days.length === 0 || allTimeSlots.length === 0) {
       return (
@@ -719,10 +727,39 @@ const ShiftPlanView: React.FC = () => {
         }}>
           Schichtplan
           <div style={{ fontSize: '14px', fontWeight: 'normal', marginTop: '5px' }}>
-            {allTimeSlots.length} Schichttypen • {days.length} Tage • Nur tatsächlich im Plan verwendete Schichten
+            {allTimeSlots.length} Zeitslots • {days.length} Tage • Zeitbasierte Darstellung
           </div>
         </div>
 
+        {/* Validation Warnings - SAME AS AVAILABILITYMANAGER */}
+        {!validation.isValid && (
+          <div style={{
+            backgroundColor: '#fff3cd',
+            border: '1px solid #ffeaa7',
+            padding: '15px',
+            margin: '10px'
+          }}>
+            <h4 style={{ margin: '0 0 10px 0', color: '#856404' }}>⚠️ Validierungswarnungen:</h4>
+            <ul style={{ margin: 0, paddingLeft: '20px', fontSize: '12px' }}>
+              {validation.errors.map((error, index) => (
+                <li key={index}>{error}</li>
+              ))}
+            </ul>
+          </div>
+        )}
+
+        {/* Timetable Structure Info - SAME AS AVAILABILITYMANAGER */}
+        <div style={{
+          backgroundColor: '#d1ecf1',
+          border: '1px solid #bee5eb',
+          padding: '10px 15px',
+          margin: '10px',
+          borderRadius: '4px',
+          fontSize: '12px'
+        }}>
+          <strong>Struktur-Info:</strong> {allTimeSlots.length} Zeitslots × {days.length} Tage = {allTimeSlots.length * days.length} Zellen
+        </div>
+
         <div style={{ overflowX: 'auto' }}>
           <table style={{
             width: '100%',
@@ -754,23 +791,32 @@ const ShiftPlanView: React.FC = () => {
               </tr>
             </thead>
             <tbody>
-              {allTimeSlots.map((timeSlot, timeIndex) => (
+              {allTimeSlots.map((timeSlot, timeSlotIndex) => (
                 <tr key={timeSlot.id} style={{
-                  backgroundColor: timeIndex % 2 === 0 ? 'white' : '#f8f9fa'
+                  backgroundColor: timeSlotIndex % 2 === 0 ? 'white' : '#f8f9fa'
                 }}>
                   <td style={{
                     padding: '12px 16px',
                     border: '1px solid #dee2e6',
                     fontWeight: '500',
-                    backgroundColor: '#f8f9fa'
+                    backgroundColor: '#f8f9fa',
+                    position: 'sticky',
+                    left: 0
                   }}>
-                    {timeSlot.displayName}
+                    <div style={{ fontWeight: 'bold' }}>
+                      {timeSlot.name}
+                    </div>
+                    <div style={{ fontSize: '14px', color: '#666' }}>
+                      {formatTime(timeSlot.startTime)} - {formatTime(timeSlot.endTime)}
+                    </div>
+                    <div style={{ fontSize: '11px', color: '#999', marginTop: '4px' }}>
+                      ID: {timeSlot.id.substring(0, 8)}...
+                    </div>
                   </td>
                   {days.map(weekday => {
-                    // Check if this time slot exists for this day
-                    const timeSlotForDay = timeSlotsByDay[weekday.id]?.find(ts => ts.id === timeSlot.id);
+                    const shift = timeSlot.shiftsByDay[weekday.id];
                     
-                    if (!timeSlotForDay) {
+                    if (!shift) {
                       return (
                         <td key={weekday.id} style={{
                           padding: '12px 16px',
@@ -780,11 +826,14 @@ const ShiftPlanView: React.FC = () => {
                           color: '#ccc',
                           fontStyle: 'italic'
                         }}>
-                          -
+                          Kein Shift
                         </td>
                       );
                     }
 
+                    // Validation: Check if shift has correct timeSlotId and dayOfWeek - SAME AS AVAILABILITYMANAGER
+                    const isValidShift = shift.timeSlotId === timeSlot.id && shift.dayOfWeek === weekday.id;
+                    
                     let assignedEmployees: string[] = [];
                     let displayText = '';
 
@@ -806,7 +855,7 @@ const ShiftPlanView: React.FC = () => {
                         
                         displayText = assignedEmployees.map(empId => {
                           const employee = employees.find(emp => emp.id === empId);
-                          return employee ? employee.email : 'Unbekannt';
+                          return employee ? `${employee.firstname} ${employee.lastname}` : 'Unbekannt';
                         }).join(', ');
                       }
                     } else if (assignmentResult) {
@@ -821,20 +870,20 @@ const ShiftPlanView: React.FC = () => {
                         assignedEmployees = getAssignmentsForScheduledShift(scheduledShift);
                         displayText = assignedEmployees.map(empId => {
                           const employee = employees.find(emp => emp.id === empId);
-                          return employee ? employee.email : 'Unbekannt';
+                          return employee ? `${employee.firstname} ${employee.lastname}` : 'Unbekannt';
                         }).join(', ');
                       }
                     }
 
                     // If no assignments yet, show empty or required count
                     if (!displayText) {
-                      const shiftsForSlot = shiftPlan?.shifts?.filter(shift => 
-                        shift.dayOfWeek === weekday.id && 
-                        shift.timeSlotId === timeSlot.id
+                      const shiftsForSlot = shiftPlan?.shifts?.filter(s => 
+                        s.dayOfWeek === weekday.id && 
+                        s.timeSlotId === timeSlot.id
                       ) || [];
                       
-                      const totalRequired = shiftsForSlot.reduce((sum, shift) => 
-                        sum + shift.requiredEmployees, 0);
+                      const totalRequired = shiftsForSlot.reduce((sum, s) => 
+                        sum + s.requiredEmployees, 0);
                       
                       // Show "0/2" instead of just "0" to indicate it's empty
                       displayText = `0/${totalRequired}`;
@@ -850,11 +899,51 @@ const ShiftPlanView: React.FC = () => {
                         padding: '12px 16px',
                         border: '1px solid #dee2e6',
                         textAlign: 'center',
-                        backgroundColor: assignedEmployees.length > 0 ? '#e8f5e8' : 'transparent',
+                        backgroundColor: !isValidShift ? '#fff3cd' : (assignedEmployees.length > 0 ? '#e8f5e8' : 'transparent'),
                         color: assignedEmployees.length > 0 ? '#2c3e50' : '#666',
-                        fontSize: assignedEmployees.length > 0 ? '14px' : 'inherit'
+                        fontSize: assignedEmployees.length > 0 ? '14px' : 'inherit',
+                        position: 'relative'
                       }}>
+                        {/* Validation indicator - SAME AS AVAILABILITYMANAGER */}
+                        {!isValidShift && (
+                          <div style={{
+                            position: 'absolute',
+                            top: '2px',
+                            right: '2px',
+                            backgroundColor: '#f39c12',
+                            color: 'white',
+                            borderRadius: '50%',
+                            width: '16px',
+                            height: '16px',
+                            fontSize: '10px',
+                            display: 'flex',
+                            alignItems: 'center',
+                            justifyContent: 'center'
+                          }}
+                          title={`Shift Validierung: timeSlotId=${shift.timeSlotId}, dayOfWeek=${shift.dayOfWeek}`}
+                          >
+                            ⚠️
+                          </div>
+                        )}
+
                         {displayText}
+
+                        {/* Shift debug info - SAME AS AVAILABILITYMANAGER */}
+                        <div style={{ 
+                          fontSize: '10px', 
+                          color: '#666', 
+                          marginTop: '4px',
+                          textAlign: 'left',
+                          fontFamily: 'monospace'
+                        }}>
+                          <div>Shift: {shift.id.substring(0, 6)}...</div>
+                          <div>Day: {shift.dayOfWeek}</div>
+                          {!isValidShift && (
+                            <div style={{ color: '#e74c3c', fontWeight: 'bold' }}>
+                              VALIDATION ERROR
+                            </div>
+                          )}
+                        </div>
                       </td>
                     );
                   })}
@@ -863,6 +952,24 @@ const ShiftPlanView: React.FC = () => {
             </tbody>
           </table>
         </div>
+
+        {/* Summary Statistics - SAME AS AVAILABILITYMANAGER */}
+        <div style={{
+          backgroundColor: '#f8f9fa',
+          padding: '15px',
+          borderTop: '1px solid #dee2e6',
+          fontSize: '12px',
+          color: '#666'
+        }}>
+          <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}>
+            <div>
+              <strong>Zusammenfassung:</strong> {allTimeSlots.length} Zeitslots × {days.length} Tage = {allTimeSlots.length * days.length} mögliche Shifts
+            </div>
+            <div>
+              <strong>Validierungsfehler:</strong> {validation.errors.length}
+            </div>
+          </div>
+        </div>
       </div>
     );
   };
@@ -872,7 +979,7 @@ const ShiftPlanView: React.FC = () => {
 
   const { days, allTimeSlots } = getTimetableData();
   const availabilityStatus = getAvailabilityStatus();
-
+  const validation = validateTimetableStructure();
 
   return (
     <div style={{ padding: '20px' }}>
@@ -938,6 +1045,50 @@ const ShiftPlanView: React.FC = () => {
         </div>
       </div>
 
+      {/* Debug Info - Enhanced */}
+      <div style={{
+        backgroundColor: validation.errors.length > 0 ? '#fff3cd' : (allTimeSlots.length === 0 ? '#f8d7da' : '#d1ecf1'),
+        border: `1px solid ${validation.errors.length > 0 ? '#ffeaa7' : (allTimeSlots.length === 0 ? '#f5c6cb' : '#bee5eb')}`,
+        borderRadius: '6px',
+        padding: '15px',
+        marginBottom: '20px'
+      }}>
+        <h4 style={{ 
+          margin: '0 0 10px 0', 
+          color: validation.errors.length > 0 ? '#856404' : (allTimeSlots.length === 0 ? '#721c24' : '#0c5460') 
+        }}>
+          {validation.errors.length > 0 ? '⚠️ VALIDIERUNGSPROBLEME' : 
+          allTimeSlots.length === 0 ? '❌ KEINE SHIFTS GEFUNDEN' : '✅ PLAN-DATEN GELADEN'}
+        </h4>
+        <div style={{ fontSize: '12px', fontFamily: 'monospace' }}>
+          <div><strong>Ausgewählter Plan:</strong> {shiftPlan.name}</div>
+          <div><strong>Plan ID:</strong> {shiftPlan.id}</div>
+          <div><strong>Einzigartige Zeitslots:</strong> {allTimeSlots.length}</div>
+          <div><strong>Verwendete Tage:</strong> {days.length} ({days.map(d => d.name).join(', ')})</div>
+          <div><strong>Shift Patterns:</strong> {shiftPlan.shifts?.length || 0}</div>
+          <div><strong>Scheduled Shifts:</strong> {scheduledShifts.length}</div>
+          <div><strong>Geladene Verfügbarkeiten:</strong> {availabilities.length}</div>
+          <div><strong>Aktive Mitarbeiter:</strong> {employees.length}</div>
+          {assignmentResult && (
+            <div><strong>Assignment Keys:</strong> {Object.keys(assignmentResult.assignments).length}</div>
+          )}
+        </div>
+
+        {/* Show shift pattern vs scheduled shift matching */}
+        {shiftPlan.shifts && scheduledShifts.length > 0 && (
+          <div style={{ marginTop: '10px', paddingTop: '10px', borderTop: '1px solid #bee5eb' }}>
+            <strong>Shift Matching:</strong>
+            <div style={{ fontSize: '11px' }}>
+              • {shiftPlan.shifts.length} Patterns → {scheduledShifts.length} Scheduled Shifts
+              {assignmentResult && (
+                <div>• {Object.keys(assignmentResult.assignments).length} Assignment Keys</div>
+              )}
+            </div>
+          </div>
+        )}
+      </div>
+
+      {/* Rest of the component remains the same... */}
       {/* Availability Status - only show for drafts */}
       {shiftPlan.status === 'draft' && (
         <div style={{
@@ -1017,8 +1168,8 @@ const ShiftPlanView: React.FC = () => {
         </div>
       )}
 
-      {/* Assignment Preview Modal */}
-      {showAssignmentPreview && assignmentResult && (
+      {/* Assignment Preview Modal - FIXED CONDITION */}
+      {(showAssignmentPreview || assignmentResult) && (
         <div style={{
           position: 'fixed',
           top: 0,
@@ -1037,12 +1188,13 @@ const ShiftPlanView: React.FC = () => {
             padding: '30px',
             maxWidth: '800px',
             maxHeight: '80vh',
-            overflow: 'auto'
+            overflow: 'auto',
+            width: '90%'
           }}>
             <h2>Wochenmuster-Zuordnung</h2>
             
             {/* Detaillierter Reparatur-Bericht anzeigen */}
-            {assignmentResult.resolutionReport && (
+            {assignmentResult?.resolutionReport && (
               <div style={{
                 backgroundColor: '#f8f9fa',
                 border: '1px solid #e9ecef',
@@ -1170,7 +1322,10 @@ const ShiftPlanView: React.FC = () => {
 
             <div style={{ display: 'flex', gap: '10px', justifyContent: 'flex-end' }}>
               <button
-                onClick={() => setShowAssignmentPreview(false)}
+                onClick={() => {
+                  setShowAssignmentPreview(false);
+                  setAssignmentResult(null);
+                }}
                 style={{
                   padding: '8px 16px',
                   backgroundColor: '#95a5a6',
@@ -1183,38 +1338,41 @@ const ShiftPlanView: React.FC = () => {
                 Abbrechen
               </button>
               
+              {/* KORRIGIERTER BUTTON MIT TYPESCRIPT-FIX */}
               <button
                 onClick={handlePublish}
-                disabled={publishing || assignmentResult.violations.filter(v => 
+                disabled={publishing || (assignmentResult ? assignmentResult.violations.filter(v => 
                   v.includes('ERROR:') || v.includes('❌ KRITISCH:')
-                ).length > 0}
+                ).length > 0 : true)}
                 style={{
                   padding: '10px 20px',
-                  backgroundColor: assignmentResult.violations.filter(v => 
+                  backgroundColor: assignmentResult ? (assignmentResult.violations.filter(v => 
                     v.includes('ERROR:') || v.includes('❌ KRITISCH:')
-                  ).length === 0 ? '#2ecc71' : '#95a5a6',
+                  ).length === 0 ? '#2ecc71' : '#95a5a6') : '#95a5a6',
                   color: 'white',
                   border: 'none',
                   borderRadius: '4px',
-                  cursor: assignmentResult.violations.filter(v => 
+                  cursor: assignmentResult ? (assignmentResult.violations.filter(v => 
                     v.includes('ERROR:') || v.includes('❌ KRITISCH:')
-                  ).length === 0 ? 'pointer' : 'not-allowed',
+                  ).length === 0 ? 'pointer' : 'not-allowed') : 'not-allowed',
                   fontWeight: 'bold',
                   fontSize: '16px'
                 }}
               >
                 {publishing ? 'Veröffentliche...' : (
-                  assignmentResult.violations.filter(v => 
-                    v.includes('ERROR:') || v.includes('❌ KRITISCH:')
-                  ).length === 0 
-                    ? 'Schichtplan veröffentlichen' 
-                    : 'Kritische Probleme müssen behoben werden'
+                  assignmentResult ? (
+                    assignmentResult.violations.filter(v => 
+                      v.includes('ERROR:') || v.includes('❌ KRITISCH:')
+                    ).length === 0 
+                      ? 'Schichtplan veröffentlichen' 
+                      : 'Kritische Probleme müssen behoben werden'
+                  ) : 'Lade Zuordnungen...'
                 )}
               </button>
             </div>
           </div>
         </div>
-      )}  
+      )}     
 
       {/* Timetable */}
       <div style={{
diff --git a/frontend/src/services/employeeService.ts b/frontend/src/services/employeeService.ts
index 925ca65..6f0b563 100644
--- a/frontend/src/services/employeeService.ts
+++ b/frontend/src/services/employeeService.ts
@@ -130,6 +130,22 @@ export class EmployeeService {
       throw new Error(error.error || 'Failed to change password');
     }
   }
+
+  async updateLastLogin(employeeId: string): Promise<void> {
+    try {
+      const response = await fetch(`${API_BASE_URL}/employees/${employeeId}/last-login`, {
+        method: 'PATCH',
+        headers: getAuthHeaders(),
+      });
+
+      if (!response.ok) {
+        throw new Error('Failed to update last login');
+      }
+    } catch (error) {
+      console.error('Error updating last login:', error);
+      throw error;
+    }
+  }
 }
 
 export const employeeService = new EmployeeService();
\ No newline at end of file