Index: Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Forms/PropertyClasses/ClosingStructuresFailureMechanismProperties.cs
===================================================================
diff -u -r6ac1d016e76120e778964de3ad7e2c0d6c837669 -rdeaf745326ef9c8e2f9d33279705b8549ef748fb
--- Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Forms/PropertyClasses/ClosingStructuresFailureMechanismProperties.cs	(.../ClosingStructuresFailureMechanismProperties.cs)	(revision 6ac1d016e76120e778964de3ad7e2c0d6c837669)
+++ Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Forms/PropertyClasses/ClosingStructuresFailureMechanismProperties.cs	(.../ClosingStructuresFailureMechanismProperties.cs)	(revision deaf745326ef9c8e2f9d33279705b8549ef748fb)
@@ -138,12 +138,8 @@
             }
             set
             {
-                IEnumerable<IObservable> affectedObjects = propertyChangeHandler.SetPropertyValueAfterConfirmation(
-                    data,
-                    value,
-                    (f, v) => f.GeneralInput.N2A = v);
-
-                NotifyAffectedObjects(affectedObjects);
+                data.GeneralInput.N2A = value;
+                data.NotifyObservers();
             }
         }
 
Index: Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.Forms.Test/PropertyClasses/ClosingStructuresFailureMechanismPropertiesTest.cs
===================================================================
diff -u -r65ce8c5ab171b234e33e2291998c9d89276db896 -rdeaf745326ef9c8e2f9d33279705b8549ef748fb
--- Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.Forms.Test/PropertyClasses/ClosingStructuresFailureMechanismPropertiesTest.cs	(.../ClosingStructuresFailureMechanismPropertiesTest.cs)	(revision 65ce8c5ab171b234e33e2291998c9d89276db896)
+++ Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.Forms.Test/PropertyClasses/ClosingStructuresFailureMechanismPropertiesTest.cs	(.../ClosingStructuresFailureMechanismPropertiesTest.cs)	(revision deaf745326ef9c8e2f9d33279705b8549ef748fb)
@@ -274,18 +274,16 @@
         {
             // Setup
             var mockRepository = new MockRepository();
-            var observable = mockRepository.StrictMock<IObservable>();
+            var observer = mockRepository.StrictMock<IObserver>();
             mockRepository.ReplayAll();
 
             var failureMechanism = new ClosingStructuresFailureMechanism();
+            failureMechanism.Attach(observer);
 
             var changeHandler = new FailureMechanismSetPropertyValueAfterConfirmationParameterTester<ClosingStructuresFailureMechanism, double>(
                 failureMechanism,
                 value,
-                new[]
-                {
-                    observable
-                });
+                new IObservable[0]);
 
             var properties = new ClosingStructuresFailureMechanismProperties(failureMechanism, changeHandler);
 
@@ -295,7 +293,6 @@
             // Assert
             const string expectedMessage = "De waarde voor 'N2A' moet in het bereik [0, 40] liggen.";
             TestHelper.AssertThrowsArgumentExceptionAndTestMessage<ArgumentOutOfRangeException>(test, expectedMessage);
-            Assert.IsTrue(changeHandler.Called);
             mockRepository.VerifyAll();
         }
 
@@ -308,19 +305,17 @@
         {
             // Setup
             var mockRepository = new MockRepository();
-            var observable = mockRepository.StrictMock<IObservable>();
-            observable.Expect(o => o.NotifyObservers());
-
+            var observer = mockRepository.StrictMock<IObserver>();
+            observer.Expect(o => o.UpdateObserver());
             mockRepository.ReplayAll();
 
             var failureMechanism = new ClosingStructuresFailureMechanism();
+            failureMechanism.Attach(observer);
+
             var changeHandler = new FailureMechanismSetPropertyValueAfterConfirmationParameterTester<ClosingStructuresFailureMechanism, double>(
                 failureMechanism,
                 value,
-                new[]
-                {
-                    observable
-                });
+                new IObservable[0]);
 
             var properties = new ClosingStructuresFailureMechanismProperties(failureMechanism, changeHandler);
 
@@ -329,7 +324,6 @@
 
             // Assert
             Assert.AreEqual(value, failureMechanism.GeneralInput.N2A);
-            Assert.IsTrue(changeHandler.Called);
             mockRepository.VerifyAll();
         }