diff --git a/functions/server/index.ts b/functions/server/index.ts
index 3eb0fdc..2d2e5ae 100644
--- a/functions/server/index.ts
+++ b/functions/server/index.ts
@@ -1,6 +1,5 @@
 import * as admin from "firebase-admin";
 import * as functions from "firebase-functions";
-import { IDepartment } from "../shared/contract/IDepartment";
 import { IStudent } from "../shared/contract/IStudent";
 import { ModelMapper } from "./ModelMapper";
 
@@ -10,42 +9,6 @@ firestore.settings({
     timestampsInSnapshots: true,
 });
 
-exports.onEducationDelete = functions.firestore.document("/educations/{id}").onDelete((snapshot) => {
-    const educationId = snapshot.id;
-
-    // Delete relations on departments
-    const departmentsPromise = firestore.collection("/departments")
-        .get()
-        .then((querySnapshot) => {
-            const innerPromises = [];
-
-            const mappedDepartments = ModelMapper.mapDocsToObjects<IDepartment>(querySnapshot.docs);
-            mappedDepartments.forEach((department) => {
-                const educations = department.capacityPerEducation;
-                if (educations === undefined || educations === null || educations.length === 0) {
-                    return;
-                }
-
-                const updatedEducations = educations.filter((edu) => edu.educationId !== educationId);
-                if (updatedEducations.length === 0) {
-                    return;
-                }
-
-                if (educations.some((edu) => edu.educationId === educationId)) {
-
-                    const updatedDepartment: Partial<IDepartment> = {
-                        capacityPerEducation: updatedEducations,
-                    };
-                    innerPromises.push(firestore.doc(`/departments/${department.id}`).update(updatedDepartment));
-                }
-            });
-
-            return Promise.all([innerPromises]);
-        });
-
-    return Promise.all([departmentsPromise]);
-});
-
 exports.onSchoolDelete = functions.firestore.document("/schools/{id}").onDelete((snapshot) => {
     const schoolId = snapshot.id;
 
diff --git a/web/src/models/ModelBase.ts b/web/src/models/ModelBase.ts
index a28508d..700d3b0 100644
--- a/web/src/models/ModelBase.ts
+++ b/web/src/models/ModelBase.ts
@@ -2,7 +2,7 @@ import moment from "moment";
 import { IFirestoreEntityBase } from "../entities/IFirestoreEntityBase";
 import { Firebase } from "../services/FirebaseInitializer";
 
-type DatabaseAction = "new" | "update";
+type DatabaseAction = "new" | "update" | "updateWithoutTime";
 
 export abstract class ModelBase<T extends IFirestoreEntityBase> {
 
@@ -22,15 +22,21 @@ export abstract class ModelBase<T extends IFirestoreEntityBase> {
             ...this.getEntityInternal(),
         };
 
+        delete entity.id;
+
         switch (databaseAction) {
             case "new":
-                delete entity.id;
                 entity.createdTimestamp = Firebase.firestore.FieldValue.serverTimestamp() as firebase.firestore.Timestamp;
                 entity.updatedTimestamp = Firebase.firestore.FieldValue.serverTimestamp() as firebase.firestore.Timestamp;
                 break;
             case "update":
+                // Make sure to not overwrite the createdTimestamp.
+                delete entity.createdTimestamp;
                 entity.updatedTimestamp = Firebase.firestore.FieldValue.serverTimestamp() as firebase.firestore.Timestamp;
                 break;
+            case "updateWithoutTime":
+                delete entity.createdTimestamp;
+                break;
             default:
                 throw new Error("Unsupported database action");
         }
diff --git a/web/src/services/repositories/DepartmentsRepository.ts b/web/src/services/repositories/DepartmentsRepository.ts
index b57fc94..bf6a608 100644
--- a/web/src/services/repositories/DepartmentsRepository.ts
+++ b/web/src/services/repositories/DepartmentsRepository.ts
@@ -1,6 +1,7 @@
 import { IDepartment } from "../../entities/IDepartment";
 import { nameof } from "../../helpers/nameof";
 import { Department } from "../../models/Department";
+import { Education } from "../../models/Education";
 import { FirebaseModelMapper } from "../FirebaseModelMapper";
 import { FirestoreRefs } from "../FirestoreRefs";
 
@@ -16,6 +17,15 @@ export class DepartmentsRepository {
             });
     }
 
+    public static async getAllDepartments(): Promise<Department[]> {
+        const querySnapshot = await FirestoreRefs.getDepartmentCollectionRef()
+            .get();
+
+        const departmentEntities = FirebaseModelMapper.mapDocsToObjects<IDepartment>(querySnapshot.docs);
+        const departments = departmentEntities.map((entity) => Department.fromEntity(entity));
+        return departments;
+    }
+
     public static async getDepartmentsByName(): Promise<Department[]> {
         const querySnapshot = await FirestoreRefs.getDepartmentCollectionRef()
             .orderBy(nameof<IDepartment>("name"), "asc")
@@ -31,12 +41,12 @@ export class DepartmentsRepository {
             .add(department.getEntity("new"));
     }
 
-    public static async updateDepartment(department: Department): Promise<void> {
+    public static async updateDepartment(department: Department, doNotUpdateTimestamp: boolean = false): Promise<void> {
         if (department.id === undefined) {
             return Promise.reject(Error("Department should have an id"));
         }
         await FirestoreRefs.getDepartmentDocRef(department.id)
-            .update(department.getEntity("update"));
+            .update(department.getEntity(doNotUpdateTimestamp ? "updateWithoutTime" : "update"));
     }
 
     public static async deleteDepartment(department: Department): Promise<void> {
@@ -46,4 +56,19 @@ export class DepartmentsRepository {
         await FirestoreRefs.getDepartmentDocRef(department.id)
             .delete();
     }
+
+    public static async deleteEducationRelations(education: Education): Promise<void> {
+        const departments = await DepartmentsRepository.getAllDepartments();
+        departments.forEach(async (department) => {
+            const educations = department.capacityPerEducation;
+            if (educations === undefined || educations === null || educations.length === 0) {
+                return;
+            }
+            if (educations.some((edu) => edu.educationId === education.id)) {
+                const educationsToKeep = educations.filter((edu) => edu.educationId !== education.id);
+                department.capacityPerEducation = educationsToKeep;
+                await DepartmentsRepository.updateDepartment(department, true);
+            }
+        });
+    }
 }
diff --git a/web/src/services/repositories/EducationsRepository.ts b/web/src/services/repositories/EducationsRepository.ts
index 8bcc2b9..047318a 100644
--- a/web/src/services/repositories/EducationsRepository.ts
+++ b/web/src/services/repositories/EducationsRepository.ts
@@ -3,6 +3,8 @@ import { nameof } from "../../helpers/nameof";
 import { Education } from "../../models/Education";
 import { FirebaseModelMapper } from "../FirebaseModelMapper";
 import { FirestoreRefs } from "../FirestoreRefs";
+import { DepartmentsRepository } from "./DepartmentsRepository";
+import { StudentsRepository } from "./StudentsRepository";
 
 export class EducationsRepository {
 
@@ -43,7 +45,18 @@ export class EducationsRepository {
         if (education.id === undefined) {
             return Promise.reject(Error("Education should have an id"));
         }
+
         await FirestoreRefs.getEducationDocRef(education.id)
             .delete();
+
+        // Delete relations on departments
+        await DepartmentsRepository.deleteEducationRelations(education);
+
+        // Delete relations on students
+        const students = await StudentsRepository.getStudentsWithEducation(education);
+        students.forEach(async (student) => {
+            student.educationId = undefined;
+            await StudentsRepository.updateStudent(student, true);
+        });
     }
 }
diff --git a/web/src/services/repositories/SchoolsRepository.ts b/web/src/services/repositories/SchoolsRepository.ts
index 03c7f0f..08b8f89 100644
--- a/web/src/services/repositories/SchoolsRepository.ts
+++ b/web/src/services/repositories/SchoolsRepository.ts
@@ -3,6 +3,7 @@ import { nameof } from "../../helpers/nameof";
 import { School } from "../../models/School";
 import { FirebaseModelMapper } from "../FirebaseModelMapper";
 import { FirestoreRefs } from "../FirestoreRefs";
+import { StudentsRepository } from "./StudentsRepository";
 
 export class SchoolsRepository {
 
@@ -45,5 +46,12 @@ export class SchoolsRepository {
         }
         await FirestoreRefs.getSchoolDocRef(school.id)
             .delete();
+
+        // Delete relations on students
+        const students = await StudentsRepository.getStudentsWithSchool(school);
+        students.forEach(async (student) => {
+            student.schoolId = undefined;
+            await StudentsRepository.updateStudent(student, true);
+        });
     }
 }
diff --git a/web/src/services/repositories/StudentsRepository.ts b/web/src/services/repositories/StudentsRepository.ts
index 3aae6c4..6ee300e 100644
--- a/web/src/services/repositories/StudentsRepository.ts
+++ b/web/src/services/repositories/StudentsRepository.ts
@@ -1,5 +1,7 @@
 import { IStudent } from "../../entities/IStudent";
 import { nameof } from "../../helpers/nameof";
+import { Education } from "../../models/Education";
+import { School } from "../../models/School";
 import { Student } from "../../models/Student";
 import { FirebaseModelMapper } from "../FirebaseModelMapper";
 import { FirestoreRefs } from "../FirestoreRefs";
@@ -28,17 +30,37 @@ export class StudentsRepository {
         return students;
     }
 
+    public static async getStudentsWithEducation(education: Education): Promise<Student[]> {
+        const querySnapshot = await FirestoreRefs.getStudentCollectionRef()
+            .where(nameof<IStudent>("educationId"), "==", education.id)
+            .get();
+
+        const studentEntities = FirebaseModelMapper.mapDocsToObjects<IStudent>(querySnapshot.docs);
+        const students = studentEntities.map((entity) => Student.fromEntity(entity));
+        return students;
+    }
+
+    public static async getStudentsWithSchool(school: School): Promise<Student[]> {
+        const querySnapshot = await FirestoreRefs.getStudentCollectionRef()
+            .where(nameof<IStudent>("schoolId"), "==", school.id)
+            .get();
+
+        const studentEntities = FirebaseModelMapper.mapDocsToObjects<IStudent>(querySnapshot.docs);
+        const students = studentEntities.map((entity) => Student.fromEntity(entity));
+        return students;
+    }
+
     public static async addStudent(student: Student): Promise<void> {
         await FirestoreRefs.getStudentCollectionRef()
             .add(student.getEntity("new"));
     }
 
-    public static async updateStudent(student: Student): Promise<void> {
+    public static async updateStudent(student: Student, doNotUpdateTimestamp: boolean = false): Promise<void> {
         if (student.id === undefined) {
             return Promise.reject(Error("Student should have an id"));
         }
         await FirestoreRefs.getStudentDocRef(student.id)
-            .update(student.getEntity("update"));
+            .update(student.getEntity(doNotUpdateTimestamp ? "updateWithoutTime" : "update"));
     }
 
     public static async deleteStudent(student: Student): Promise<void> {