Index: Riskeer/GrassCoverErosionOutwards/src/Riskeer.GrassCoverErosionOutwards.Forms/PropertyClasses/GrassCoverErosionOutwardsFailurePathProperties.cs
===================================================================
diff -u -re0dbdfb3d8e3e614cefb7aa240f92a0fc2309ccc -re727a4e22432d443b1bd2d24667e1e8c9746d73c
--- Riskeer/GrassCoverErosionOutwards/src/Riskeer.GrassCoverErosionOutwards.Forms/PropertyClasses/GrassCoverErosionOutwardsFailurePathProperties.cs	(.../GrassCoverErosionOutwardsFailurePathProperties.cs)	(revision e0dbdfb3d8e3e614cefb7aa240f92a0fc2309ccc)
+++ Riskeer/GrassCoverErosionOutwards/src/Riskeer.GrassCoverErosionOutwards.Forms/PropertyClasses/GrassCoverErosionOutwardsFailurePathProperties.cs	(.../GrassCoverErosionOutwardsFailurePathProperties.cs)	(revision e727a4e22432d443b1bd2d24667e1e8c9746d73c)
@@ -20,12 +20,9 @@
 // All rights reserved.
 
 using System;
-using System.Collections.Generic;
-using Core.Common.Base;
 using Core.Common.Base.Data;
 using Core.Common.Util.Attributes;
 using Core.Gui.Attributes;
-using Riskeer.Common.Forms.PropertyClasses;
 using Riskeer.GrassCoverErosionOutwards.Data;
 using RiskeerCommonFormsResources = Riskeer.Common.Forms.Properties.Resources;
 
@@ -41,31 +38,20 @@
         private const int groupPropertyIndex = 3;
         private const int contributionPropertyIndex = 4;
         private const int nPropertyIndex = 5;
-        private readonly IFailureMechanismPropertyChangeHandler<GrassCoverErosionOutwardsFailureMechanism> propertyChangeHandler;
 
         /// <summary>
         /// Creates a new instance of <see cref="GrassCoverErosionOutwardsFailurePathProperties"/>.
         /// </summary>
         /// <param name="data">The instance to show the properties of.</param>
-        /// <param name="handler">Handler responsible for handling effects of a property change.</param>
         /// <exception cref="ArgumentNullException">Thrown when any parameter is <c>null</c>.</exception>
-        public GrassCoverErosionOutwardsFailurePathProperties(
-            GrassCoverErosionOutwardsFailureMechanism data,
-            IFailureMechanismPropertyChangeHandler<GrassCoverErosionOutwardsFailureMechanism> handler) : base(data, new ConstructionProperties
-        {
-            NamePropertyIndex = namePropertyIndex,
-            CodePropertyIndex = codePropertyIndex,
-            GroupPropertyIndex = groupPropertyIndex,
-            ContributionPropertyIndex = contributionPropertyIndex
-        })
-        {
-            if (handler == null)
+        public GrassCoverErosionOutwardsFailurePathProperties(GrassCoverErosionOutwardsFailureMechanism data)
+            : base(data, new ConstructionProperties
             {
-                throw new ArgumentNullException(nameof(handler));
-            }
-            
-            propertyChangeHandler = handler;
-        }
+                NamePropertyIndex = namePropertyIndex,
+                CodePropertyIndex = codePropertyIndex,
+                GroupPropertyIndex = groupPropertyIndex,
+                ContributionPropertyIndex = contributionPropertyIndex
+            }) {}
 
         #region Length effect parameters
 
@@ -81,23 +67,11 @@
             }
             set
             {
-                IEnumerable<IObservable> affectedObjects = propertyChangeHandler.SetPropertyValueAfterConfirmation(
-                    data,
-                    value,
-                    (f, v) => f.GeneralInput.N = v);
-
-                NotifyAffectedObjects(affectedObjects);
+                data.GeneralInput.N = value;
+                data.NotifyObservers();
             }
         }
 
         #endregion
-
-        private static void NotifyAffectedObjects(IEnumerable<IObservable> affectedObjects)
-        {
-            foreach (IObservable affectedObject in affectedObjects)
-            {
-                affectedObject.NotifyObservers();
-            }
-        }
     }
 }
\ No newline at end of file
Index: Riskeer/GrassCoverErosionOutwards/src/Riskeer.GrassCoverErosionOutwards.Forms/PropertyClasses/GrassCoverErosionOutwardsHydraulicLoadsProperties.cs
===================================================================
diff -u -re0dbdfb3d8e3e614cefb7aa240f92a0fc2309ccc -re727a4e22432d443b1bd2d24667e1e8c9746d73c
--- Riskeer/GrassCoverErosionOutwards/src/Riskeer.GrassCoverErosionOutwards.Forms/PropertyClasses/GrassCoverErosionOutwardsHydraulicLoadsProperties.cs	(.../GrassCoverErosionOutwardsHydraulicLoadsProperties.cs)	(revision e0dbdfb3d8e3e614cefb7aa240f92a0fc2309ccc)
+++ Riskeer/GrassCoverErosionOutwards/src/Riskeer.GrassCoverErosionOutwards.Forms/PropertyClasses/GrassCoverErosionOutwardsHydraulicLoadsProperties.cs	(.../GrassCoverErosionOutwardsHydraulicLoadsProperties.cs)	(revision e727a4e22432d443b1bd2d24667e1e8c9746d73c)
@@ -48,14 +48,14 @@
         /// </summary>
         /// <param name="data">The instance to show the properties of.</param>
         /// <exception cref="ArgumentNullException">Thrown when <paramref name="data"/> is <c>null</c>.</exception>
-        public GrassCoverErosionOutwardsHydraulicLoadsProperties(
-            GrassCoverErosionOutwardsFailureMechanism data) : base(data, new ConstructionProperties
-        {
-            NamePropertyIndex = namePropertyIndex,
-            CodePropertyIndex = codePropertyIndex,
-            GroupPropertyIndex = groupPropertyIndex,
-            ContributionPropertyIndex = contributionPropertyIndex
-        }) {}
+        public GrassCoverErosionOutwardsHydraulicLoadsProperties(GrassCoverErosionOutwardsFailureMechanism data)
+            : base(data, new ConstructionProperties
+            {
+                NamePropertyIndex = namePropertyIndex,
+                CodePropertyIndex = codePropertyIndex,
+                GroupPropertyIndex = groupPropertyIndex,
+                ContributionPropertyIndex = contributionPropertyIndex
+            }) {}
 
         #region Model settings
 
Index: Riskeer/GrassCoverErosionOutwards/src/Riskeer.GrassCoverErosionOutwards.Plugin/GrassCoverErosionOutwardsPlugin.cs
===================================================================
diff -u -re0dbdfb3d8e3e614cefb7aa240f92a0fc2309ccc -re727a4e22432d443b1bd2d24667e1e8c9746d73c
--- Riskeer/GrassCoverErosionOutwards/src/Riskeer.GrassCoverErosionOutwards.Plugin/GrassCoverErosionOutwardsPlugin.cs	(.../GrassCoverErosionOutwardsPlugin.cs)	(revision e0dbdfb3d8e3e614cefb7aa240f92a0fc2309ccc)
+++ Riskeer/GrassCoverErosionOutwards/src/Riskeer.GrassCoverErosionOutwards.Plugin/GrassCoverErosionOutwardsPlugin.cs	(.../GrassCoverErosionOutwardsPlugin.cs)	(revision e727a4e22432d443b1bd2d24667e1e8c9746d73c)
@@ -77,8 +77,7 @@
             yield return new PropertyInfo<GrassCoverErosionOutwardsFailurePathContext, GrassCoverErosionOutwardsFailurePathProperties>
             {
                 CreateInstance = context => new GrassCoverErosionOutwardsFailurePathProperties(
-                    context.WrappedData,
-                    new FailureMechanismPropertyChangeHandler<GrassCoverErosionOutwardsFailureMechanism>())
+                    context.WrappedData)
             };
 
             yield return new PropertyInfo<GrassCoverErosionOutwardsWaveConditionsOutputContext, GrassCoverErosionOutwardsWaveConditionsOutputProperties>
Index: Riskeer/GrassCoverErosionOutwards/test/Riskeer.GrassCoverErosionOutwards.Forms.Test/PropertyClasses/GrassCoverErosionOutwardsFailurePathPropertiesTest.cs
===================================================================
diff -u -re0dbdfb3d8e3e614cefb7aa240f92a0fc2309ccc -re727a4e22432d443b1bd2d24667e1e8c9746d73c
--- Riskeer/GrassCoverErosionOutwards/test/Riskeer.GrassCoverErosionOutwards.Forms.Test/PropertyClasses/GrassCoverErosionOutwardsFailurePathPropertiesTest.cs	(.../GrassCoverErosionOutwardsFailurePathPropertiesTest.cs)	(revision e0dbdfb3d8e3e614cefb7aa240f92a0fc2309ccc)
+++ Riskeer/GrassCoverErosionOutwards/test/Riskeer.GrassCoverErosionOutwards.Forms.Test/PropertyClasses/GrassCoverErosionOutwardsFailurePathPropertiesTest.cs	(.../GrassCoverErosionOutwardsFailurePathPropertiesTest.cs)	(revision e727a4e22432d443b1bd2d24667e1e8c9746d73c)
@@ -28,8 +28,6 @@
 using NUnit.Framework;
 using Rhino.Mocks;
 using Riskeer.Common.Data.TestUtil;
-using Riskeer.Common.Forms.PropertyClasses;
-using Riskeer.Common.Forms.TestUtil;
 using Riskeer.GrassCoverErosionOutwards.Data;
 using Riskeer.GrassCoverErosionOutwards.Forms.PropertyClasses;
 
@@ -45,28 +43,13 @@
         private const int nPropertyIndex = 4;
 
         [Test]
-        public void Constructor_ChangeHandlerNull_ThrowsArgumentNullException()
-        {
-            // Call
-            void Call() => new GrassCoverErosionOutwardsFailurePathProperties(new GrassCoverErosionOutwardsFailureMechanism(), null);
-
-            // Assert
-            var exception = Assert.Throws<ArgumentNullException>(Call);
-            Assert.AreEqual("handler", exception.ParamName);
-        }
-
-        [Test]
         public void Constructor_ExpectedValues()
         {
             // Setup
-            var mocks = new MockRepository();
-            var handler = mocks.Stub<IFailureMechanismPropertyChangeHandler<GrassCoverErosionOutwardsFailureMechanism>>();
-            mocks.ReplayAll();
-
             var failureMechanism = new GrassCoverErosionOutwardsFailureMechanism();
 
             // Call
-            var properties = new GrassCoverErosionOutwardsFailurePathProperties(failureMechanism, handler);
+            var properties = new GrassCoverErosionOutwardsFailurePathProperties(failureMechanism);
 
             // Assert
             Assert.IsInstanceOf<GrassCoverErosionOutwardsFailureMechanismProperties>(properties);
@@ -80,22 +63,16 @@
             Assert.AreEqual(generalInput.N,
                             properties.N,
                             properties.N.GetAccuracy());
-
-            mocks.VerifyAll();
         }
 
         [Test]
         public void Constructor_Always_PropertiesHaveExpectedAttributesValues()
         {
             // Setup
-            var mocks = new MockRepository();
-            var handler = mocks.Stub<IFailureMechanismPropertyChangeHandler<GrassCoverErosionOutwardsFailureMechanism>>();
-            mocks.ReplayAll();
-
             var failureMechanism = new GrassCoverErosionOutwardsFailureMechanism();
 
             // Call
-            var properties = new GrassCoverErosionOutwardsFailurePathProperties(failureMechanism, handler);
+            var properties = new GrassCoverErosionOutwardsFailurePathProperties(failureMechanism);
 
             // Assert
             PropertyDescriptorCollection dynamicProperties = PropertiesTestHelper.GetAllVisiblePropertyDescriptors(properties);
@@ -137,8 +114,6 @@
                                                                             lengthEffectCategory,
                                                                             "N [-]",
                                                                             "De parameter 'N' die gebruikt wordt om het lengte-effect mee te nemen in de beoordeling.");
-
-            mocks.VerifyAll();
         }
 
         [Test]
@@ -150,27 +125,20 @@
         {
             // Setup
             var mocks = new MockRepository();
-            var observable = mocks.StrictMock<IObservable>();
+            var observer = mocks.StrictMock<IObserver>();
             mocks.ReplayAll();
 
             var failureMechanism = new GrassCoverErosionOutwardsFailureMechanism();
-            var handler = new FailureMechanismSetPropertyValueAfterConfirmationParameterTester<GrassCoverErosionOutwardsFailureMechanism, double>(
-                failureMechanism,
-                newN,
-                new[]
-                {
-                    observable
-                });
+            failureMechanism.Attach(observer);
 
-            var properties = new GrassCoverErosionOutwardsFailurePathProperties(failureMechanism, handler);
+            var properties = new GrassCoverErosionOutwardsFailurePathProperties(failureMechanism);
 
             // Call
             void Call() => properties.N = (RoundedDouble) newN;
 
             // Assert
             const string expectedMessage = "De waarde voor 'N' moet in het bereik [1,00, 20,00] liggen.";
             TestHelper.AssertThrowsArgumentExceptionAndTestMessage<ArgumentOutOfRangeException>(Call, expectedMessage);
-            Assert.IsTrue(handler.Called);
 
             mocks.VerifyAll();
         }
@@ -183,27 +151,20 @@
         {
             // Setup
             var mocks = new MockRepository();
-            var observable = mocks.StrictMock<IObservable>();
-            observable.Expect(o => o.NotifyObservers());
+            var observer = mocks.StrictMock<IObserver>();
+            observer.Expect(o => o.UpdateObserver());
             mocks.ReplayAll();
 
             var failureMechanism = new GrassCoverErosionOutwardsFailureMechanism();
-            var handler = new FailureMechanismSetPropertyValueAfterConfirmationParameterTester<GrassCoverErosionOutwardsFailureMechanism, double>(
-                failureMechanism,
-                newN,
-                new[]
-                {
-                    observable
-                });
+            failureMechanism.Attach(observer);
 
-            var properties = new GrassCoverErosionOutwardsFailurePathProperties(failureMechanism, handler);
+            var properties = new GrassCoverErosionOutwardsFailurePathProperties(failureMechanism);
 
             // Call
             properties.N = (RoundedDouble) newN;
 
             // Assert
-            Assert.AreEqual(newN, failureMechanism.GeneralInput.N);
-            Assert.IsTrue(handler.Called);
+            Assert.AreEqual(newN, failureMechanism.GeneralInput.N, failureMechanism.GeneralInput.N.GetAccuracy());
 
             mocks.VerifyAll();
         }
Index: Riskeer/GrassCoverErosionOutwards/test/Riskeer.GrassCoverErosionOutwards.Forms.Test/PropertyClasses/GrassCoverErosionOutwardsHydraulicLoadsPropertiesTest.cs
===================================================================
diff -u -re0dbdfb3d8e3e614cefb7aa240f92a0fc2309ccc -re727a4e22432d443b1bd2d24667e1e8c9746d73c
--- Riskeer/GrassCoverErosionOutwards/test/Riskeer.GrassCoverErosionOutwards.Forms.Test/PropertyClasses/GrassCoverErosionOutwardsHydraulicLoadsPropertiesTest.cs	(.../GrassCoverErosionOutwardsHydraulicLoadsPropertiesTest.cs)	(revision e0dbdfb3d8e3e614cefb7aa240f92a0fc2309ccc)
+++ Riskeer/GrassCoverErosionOutwards/test/Riskeer.GrassCoverErosionOutwards.Forms.Test/PropertyClasses/GrassCoverErosionOutwardsHydraulicLoadsPropertiesTest.cs	(.../GrassCoverErosionOutwardsHydraulicLoadsPropertiesTest.cs)	(revision e727a4e22432d443b1bd2d24667e1e8c9746d73c)
@@ -64,7 +64,8 @@
 
         [Test]
         public void Constructor_Always_PropertiesHaveExpectedAttributeValues()
-        { // Call
+        {
+            // Call
             var properties = new GrassCoverErosionOutwardsHydraulicLoadsProperties(new GrassCoverErosionOutwardsFailureMechanism());
 
             // Assert