Index: Riskeer/Common/src/Riskeer.Common.Data/FailurePath/FailurePathAssemblyResult.cs
===================================================================
diff -u -r201bafea43b47457fe3c571604a492e2b1da39e6 -rb32307a144c2b5dd2d795596c3e7dd53961787db
--- Riskeer/Common/src/Riskeer.Common.Data/FailurePath/FailurePathAssemblyResult.cs	(.../FailurePathAssemblyResult.cs)	(revision 201bafea43b47457fe3c571604a492e2b1da39e6)
+++ Riskeer/Common/src/Riskeer.Common.Data/FailurePath/FailurePathAssemblyResult.cs	(.../FailurePathAssemblyResult.cs)	(revision b32307a144c2b5dd2d795596c3e7dd53961787db)
@@ -20,6 +20,7 @@
 // All rights reserved.
 
 using System;
+using Core.Common.Base;
 using Riskeer.Common.Data.Probability;
 using RiskeerCommonDataResources = Riskeer.Common.Data.Properties.Resources;
 
@@ -28,7 +29,7 @@
     /// <summary>
     /// Class containing the assembly result of an entire failure path.
     /// </summary>
-    public class FailurePathAssemblyResult
+    public class FailurePathAssemblyResult : Observable
     {
         private double manualFailurePathAssemblyProbability;
 
Index: Riskeer/Common/src/Riskeer.Common.Forms/Views/FailureMechanismResultView.cs
===================================================================
diff -u -rfa2555e568efcf9d88e7141367dbcfb4983a8cae -rb32307a144c2b5dd2d795596c3e7dd53961787db
--- Riskeer/Common/src/Riskeer.Common.Forms/Views/FailureMechanismResultView.cs	(.../FailureMechanismResultView.cs)	(revision fa2555e568efcf9d88e7141367dbcfb4983a8cae)
+++ Riskeer/Common/src/Riskeer.Common.Forms/Views/FailureMechanismResultView.cs	(.../FailureMechanismResultView.cs)	(revision b32307a144c2b5dd2d795596c3e7dd53961787db)
@@ -120,7 +120,9 @@
             {
                 if (IsManualAssembly())
                 {
-                    FailureMechanism.AssemblyResult.ManualFailurePathAssemblyProbability = value;
+                    FailurePathAssemblyResult assemblyResult = FailureMechanism.AssemblyResult;
+                    assemblyResult.ManualFailurePathAssemblyProbability = value;
+                    assemblyResult.NotifyObservers();
                 }
 
                 failurePathAssemblyProbability = value;
@@ -322,7 +324,9 @@
                 return;
             }
 
-            FailureMechanism.AssemblyResult.ProbabilityResultType = (FailurePathAssemblyProbabilityResultType) probabilityResultTypeComboBox.SelectedValue;
+            FailurePathAssemblyResult assemblyResult = FailureMechanism.AssemblyResult;
+            assemblyResult.ProbabilityResultType = (FailurePathAssemblyProbabilityResultType) probabilityResultTypeComboBox.SelectedValue;
+            assemblyResult.NotifyObservers();
             
             UpdateAssemblyData();
             UpdateFailurePathAssemblyControls();
Index: Riskeer/Common/test/Riskeer.Common.Data.Test/FailurePath/FailurePathAssemblyResultTest.cs
===================================================================
diff -u -rf021c1bffb41b07a8f60f9d96dcf2a08f9fc03cf -rb32307a144c2b5dd2d795596c3e7dd53961787db
--- Riskeer/Common/test/Riskeer.Common.Data.Test/FailurePath/FailurePathAssemblyResultTest.cs	(.../FailurePathAssemblyResultTest.cs)	(revision f021c1bffb41b07a8f60f9d96dcf2a08f9fc03cf)
+++ Riskeer/Common/test/Riskeer.Common.Data.Test/FailurePath/FailurePathAssemblyResultTest.cs	(.../FailurePathAssemblyResultTest.cs)	(revision b32307a144c2b5dd2d795596c3e7dd53961787db)
@@ -20,6 +20,7 @@
 // All rights reserved.
 
 using System;
+using Core.Common.Base;
 using Core.Common.TestUtil;
 using NUnit.Framework;
 using Riskeer.Common.Data.FailurePath;
@@ -36,6 +37,8 @@
             var result = new FailurePathAssemblyResult();
 
             // Assert
+            Assert.IsInstanceOf<Observable>(result);
+            
             Assert.AreEqual(FailurePathAssemblyProbabilityResultType.Automatic, result.ProbabilityResultType);
             Assert.IsNaN(result.ManualFailurePathAssemblyProbability);
         }
Index: Riskeer/Common/test/Riskeer.Common.Forms.Test/Views/FailureMechanismResultViewTest.cs
===================================================================
diff -u -rfa2555e568efcf9d88e7141367dbcfb4983a8cae -rb32307a144c2b5dd2d795596c3e7dd53961787db
--- Riskeer/Common/test/Riskeer.Common.Forms.Test/Views/FailureMechanismResultViewTest.cs	(.../FailureMechanismResultViewTest.cs)	(revision fa2555e568efcf9d88e7141367dbcfb4983a8cae)
+++ Riskeer/Common/test/Riskeer.Common.Forms.Test/Views/FailureMechanismResultViewTest.cs	(.../FailureMechanismResultViewTest.cs)	(revision b32307a144c2b5dd2d795596c3e7dd53961787db)
@@ -804,7 +804,8 @@
             // Given
             var mocks = new MockRepository();
             var observer = mocks.StrictMock<IObserver>();
-            observer.Expect(o => o.UpdateObserver());
+            observer.Expect(o => o.UpdateObserver())
+                    .Repeat.Twice();
             mocks.ReplayAll();
 
             var failureMechanism = new TestFailureMechanism
@@ -814,7 +815,7 @@
                     ProbabilityResultType = FailurePathAssemblyProbabilityResultType.Automatic
                 }
             };
-            failureMechanism.Attach(observer);
+            failureMechanism.AssemblyResult.Attach(observer);
 
             using (new AssemblyToolCalculatorFactoryConfig())
             using (ShowFailureMechanismResultsView(failureMechanism, failureMechanism.SectionResults))
@@ -908,7 +909,8 @@
 
             var mocks = new MockRepository();
             var observer = mocks.StrictMock<IObserver>();
-            observer.Expect(o => o.UpdateObserver());
+            observer.Expect(o => o.UpdateObserver())
+                    .Repeat.Twice();
             mocks.ReplayAll();
 
             var failureMechanism = new TestFailureMechanism
@@ -919,7 +921,7 @@
                     ManualFailurePathAssemblyProbability = manualProbability
                 }
             };
-            failureMechanism.Attach(observer);
+            failureMechanism.AssemblyResult.Attach(observer);
 
             using (TestFailureMechanismResultView view = ShowFailureMechanismResultsView(failureMechanism, failureMechanism.SectionResults))
             {
@@ -967,7 +969,6 @@
                     ProbabilityResultType = FailurePathAssemblyProbabilityResultType.Manual
                 }
             };
-            failureMechanism.Attach(observer);
 
             using (TestFailureMechanismResultView view = ShowFailureMechanismResultsView(failureMechanism, failureMechanism.SectionResults))
             {
@@ -980,6 +981,8 @@
                 string errorMessage = errorProvider.GetError(failurePathAssemblyProbabilityTextBox);
                 Assert.IsNotEmpty(errorMessage);
 
+                failureMechanism.AssemblyResult.Attach(observer);
+
                 // When
                 textBoxTester.Enter(validValue);