Index: Riskeer/Common/src/Riskeer.Common.Forms/TreeNodeInfos/RiskeerContextMenuItemFactory.cs
===================================================================
diff -u -ra54668f67eba8b3498b65e9117a2e0af0b9840c8 -re3e21a866796ff70c0b7b28dfba268aae164ff33
--- Riskeer/Common/src/Riskeer.Common.Forms/TreeNodeInfos/RiskeerContextMenuItemFactory.cs	(.../RiskeerContextMenuItemFactory.cs)	(revision a54668f67eba8b3498b65e9117a2e0af0b9840c8)
+++ Riskeer/Common/src/Riskeer.Common.Forms/TreeNodeInfos/RiskeerContextMenuItemFactory.cs	(.../RiskeerContextMenuItemFactory.cs)	(revision e3e21a866796ff70c0b7b28dfba268aae164ff33)
@@ -294,23 +294,26 @@
         /// <summary>
         /// Creates a <see cref="StrictContextMenuItem"/> which is bound to the action of clearing the output of all calculations in a failure mechanism.
         /// </summary>
-        /// <param name="failureMechanism">The failure mechanism to clear the output for.</param>
+        /// <param name="isContextItemEnabledFunc">The function to determine whether the context menu item should be enabled.</param>
+        /// <param name="changeHandler">Object responsible for clearing the calculation output.</param>
         /// <returns>The created <see cref="StrictContextMenuItem"/>.</returns>
-        public static StrictContextMenuItem CreateClearAllCalculationOutputInFailureMechanismItem(IFailureMechanism failureMechanism)
+        public static StrictContextMenuItem CreateClearAllCalculationOutputInFailureMechanismItem(
+            Func<bool> isContextItemEnabledFunc, IClearCalculationOutputChangeHandler changeHandler)
         {
-            var clearAllItem = new StrictContextMenuItem(
+            bool enabled = isContextItemEnabledFunc();
+
+            string toolTip = enabled
+                                 ? Resources.Clear_all_output_ToolTip
+                                 : Resources.CalculationGroup_ClearOutput_No_calculation_with_output_to_clear;
+
+            return new StrictContextMenuItem(
                 Resources.Clear_all_output,
-                Resources.Clear_all_output_ToolTip,
+                toolTip,
                 Resources.ClearIcon,
-                (o, args) => ClearAllCalculationOutputInFailureMechanism(failureMechanism));
-
-            if (!failureMechanism.Calculations.Any(c => c.HasOutput))
+                (o, args) => ClearAllCalculationOutputInFailureMechanism(changeHandler))
             {
-                clearAllItem.Enabled = false;
-                clearAllItem.ToolTipText = Resources.CalculationGroup_ClearOutput_No_calculation_with_output_to_clear;
-            }
-
-            return clearAllItem;
+                Enabled = enabled
+            };
         }
 
         /// <summary>
@@ -640,18 +643,13 @@
             }
         }
 
-        private static void ClearAllCalculationOutputInFailureMechanism(IFailureMechanism failureMechanism)
+        private static void ClearAllCalculationOutputInFailureMechanism(IClearCalculationOutputChangeHandler changeHandler)
         {
-            if (MessageBox.Show(Resources.FailureMechanism_ContextMenuStrip_Are_you_sure_clear_all_output, BaseResources.Confirm, MessageBoxButtons.OKCancel) != DialogResult.OK)
+            if (changeHandler.InquireConfirmation())
             {
-                return;
+                IEnumerable<IObservable> affectedObjects = changeHandler.ClearCalculations();
+                affectedObjects.ForEachElementDo(o => o.NotifyObservers());
             }
-
-            foreach (ICalculation calc in failureMechanism.Calculations.Where(c => c.HasOutput))
-            {
-                calc.ClearOutput();
-                calc.NotifyObservers();
-            }
         }
 
         private static void CreateCalculationGroup(CalculationGroup calculationGroup)
Index: Riskeer/Common/test/Riskeer.Common.Forms.Test/TreeNodeInfos/RiskeerContextMenuItemFactoryTest.cs
===================================================================
diff -u -ra54668f67eba8b3498b65e9117a2e0af0b9840c8 -re3e21a866796ff70c0b7b28dfba268aae164ff33
--- Riskeer/Common/test/Riskeer.Common.Forms.Test/TreeNodeInfos/RiskeerContextMenuItemFactoryTest.cs	(.../RiskeerContextMenuItemFactoryTest.cs)	(revision a54668f67eba8b3498b65e9117a2e0af0b9840c8)
+++ Riskeer/Common/test/Riskeer.Common.Forms.Test/TreeNodeInfos/RiskeerContextMenuItemFactoryTest.cs	(.../RiskeerContextMenuItemFactoryTest.cs)	(revision e3e21a866796ff70c0b7b28dfba268aae164ff33)
@@ -312,18 +312,12 @@
         {
             // Setup
             var mocks = new MockRepository();
-            var calculationWithOutput = mocks.StrictMock<ICalculation>();
-            calculationWithOutput.Expect(c => c.HasOutput).Return(true);
-            var failureMechanism = mocks.StrictMock<IFailureMechanism>();
-            failureMechanism.Expect(fm => fm.Calculations).Return(new[]
-            {
-                calculationWithOutput
-            });
-
+            var changeHandler = mocks.Stub<IClearCalculationOutputChangeHandler>();
             mocks.ReplayAll();
 
             // Call
-            StrictContextMenuItem toolStripItem = RiskeerContextMenuItemFactory.CreateClearAllCalculationOutputInFailureMechanismItem(failureMechanism);
+            StrictContextMenuItem toolStripItem = RiskeerContextMenuItemFactory.CreateClearAllCalculationOutputInFailureMechanismItem(
+                () => true, changeHandler);
 
             // Assert
             Assert.AreEqual("&Wis alle uitvoer...", toolStripItem.Text);
@@ -339,17 +333,12 @@
         {
             // Setup
             var mocks = new MockRepository();
-            var calculationWithoutOutput = mocks.StrictMock<ICalculation>();
-            calculationWithoutOutput.Expect(c => c.HasOutput).Return(false);
-            var failureMechanism = mocks.StrictMock<IFailureMechanism>();
-            failureMechanism.Expect(fm => fm.Calculations).Return(new[]
-            {
-                calculationWithoutOutput
-            });
+            var changeHandler = mocks.Stub<IClearCalculationOutputChangeHandler>();
             mocks.ReplayAll();
 
             // Call
-            StrictContextMenuItem toolStripItem = RiskeerContextMenuItemFactory.CreateClearAllCalculationOutputInFailureMechanismItem(failureMechanism);
+            StrictContextMenuItem toolStripItem = RiskeerContextMenuItemFactory.CreateClearAllCalculationOutputInFailureMechanismItem(
+                () => false, changeHandler);
 
             // Assert
             Assert.AreEqual("&Wis alle uitvoer...", toolStripItem.Text);
@@ -361,84 +350,54 @@
         }
 
         [Test]
-        public void CreateClearAllCalculationOutputInFailureMechanismItem_PerformClickOnCreatedItemAndConfirmChange_CalculationOutputClearedAndObserversNotified()
+        public void GivenCreateClearAllCalculationOutputInFailureMechanismItem_WhenClickPerformedAndActionContinued_ThenClearCalculationsPerformedAndObserversNotified()
         {
-            // Setup
+            // Given
             var mocks = new MockRepository();
-            var calculationWithOutputMock1 = mocks.StrictMock<ICalculation>();
-            var calculationWithOutputMock2 = mocks.StrictMock<ICalculation>();
-            var calculationWithoutOutput = mocks.StrictMock<ICalculation>();
+            var calculation1 = mocks.StrictMock<ICalculation>();
+            var calculation2 = mocks.StrictMock<ICalculation>();
+            var calculation3 = mocks.StrictMock<ICalculation>();
 
-            calculationWithOutputMock1.Stub(c => c.HasOutput).Return(true);
-            calculationWithOutputMock2.Stub(c => c.HasOutput).Return(true);
-            calculationWithoutOutput.Stub(c => c.HasOutput).Return(false);
-
-            calculationWithOutputMock1.Expect(c => c.ClearOutput());
-            calculationWithOutputMock1.Expect(c => c.NotifyObservers());
-            calculationWithOutputMock2.Expect(c => c.ClearOutput());
-            calculationWithOutputMock2.Expect(c => c.NotifyObservers());
-
-            var failureMechanism = new TestFailureMechanism(new[]
+            var changeHandler = mocks.StrictMock<IClearCalculationOutputChangeHandler>();
+            changeHandler.Expect(ch => ch.InquireConfirmation()).Return(true);
+            changeHandler.Expect(ch => ch.ClearCalculations()).Return(new[]
             {
-                calculationWithOutputMock1,
-                calculationWithOutputMock2,
-                calculationWithoutOutput
+                calculation1,
+                calculation2,
+                calculation3
             });
 
+            calculation1.Expect(c => c.NotifyObservers());
+            calculation2.Expect(c => c.NotifyObservers());
+            calculation3.Expect(c => c.NotifyObservers());
             mocks.ReplayAll();
 
-            DialogBoxHandler = (name, wnd) =>
-            {
-                var messageBox = new MessageBoxTester(wnd);
+            StrictContextMenuItem toolStripItem = RiskeerContextMenuItemFactory.CreateClearAllCalculationOutputInFailureMechanismItem(
+                () => true, changeHandler);
 
-                messageBox.ClickOk();
-            };
-
-            StrictContextMenuItem toolStripItem = RiskeerContextMenuItemFactory.CreateClearAllCalculationOutputInFailureMechanismItem(failureMechanism);
-
-            // Call
+            // When
             toolStripItem.PerformClick();
 
-            // Assert
+            // Then
             mocks.VerifyAll();
         }
 
         [Test]
-        public void CreateClearAllCalculationOutputInFailureMechanismItem_PerformClickOnCreatedItemAndCancelChange_CalculationOutputNotCleared()
+        public void GivenCreateClearAllCalculationOutputInFailureMechanismItem_WhenWhenClickPerformedAndActionCancelled_ThenNothingHappens()
         {
-            // Setup
+            // Given
             var mocks = new MockRepository();
-            var calculationWithOutputMock1 = mocks.StrictMock<ICalculation>();
-            var calculationWithOutputMock2 = mocks.StrictMock<ICalculation>();
-            var calculationWithoutOutput = mocks.StrictMock<ICalculation>();
-
-            calculationWithOutputMock1.Stub(c => c.HasOutput).Return(true);
-            calculationWithOutputMock2.Stub(c => c.HasOutput).Return(true);
-            calculationWithoutOutput.Stub(c => c.HasOutput).Return(false);
-
-            var failureMechanism = mocks.StrictMock<IFailureMechanism>();
-            failureMechanism.Expect(fm => fm.Calculations).Return(new[]
-            {
-                calculationWithOutputMock1,
-                calculationWithOutputMock2,
-                calculationWithoutOutput
-            });
-
+            var changeHandler = mocks.StrictMock<IClearCalculationOutputChangeHandler>();
+            changeHandler.Expect(ch => ch.InquireConfirmation()).Return(false);
             mocks.ReplayAll();
 
-            DialogBoxHandler = (name, wnd) =>
-            {
-                var messageBox = new MessageBoxTester(wnd);
+            StrictContextMenuItem toolStripItem = RiskeerContextMenuItemFactory.CreateClearAllCalculationOutputInFailureMechanismItem(
+                () => true, changeHandler);
 
-                messageBox.ClickCancel();
-            };
-
-            StrictContextMenuItem toolStripItem = RiskeerContextMenuItemFactory.CreateClearAllCalculationOutputInFailureMechanismItem(failureMechanism);
-
-            // Call
+            // When
             toolStripItem.PerformClick();
 
-            // Assert
+            // Then
             mocks.VerifyAll();
         }