Index: src/Plugins/Ringtoets/Piping/src/Ringtoets.Piping.Data/PipingFailureMechanism.cs
===================================================================
diff -u -r300a33d9acf653458b834b296becbf9ae552de8e -rdf0cc3cc798c0d57715d9dbe78b71387066913b5
--- src/Plugins/Ringtoets/Piping/src/Ringtoets.Piping.Data/PipingFailureMechanism.cs	(.../PipingFailureMechanism.cs)	(revision 300a33d9acf653458b834b296becbf9ae552de8e)
+++ src/Plugins/Ringtoets/Piping/src/Ringtoets.Piping.Data/PipingFailureMechanism.cs	(.../PipingFailureMechanism.cs)	(revision df0cc3cc798c0d57715d9dbe78b71387066913b5)
@@ -20,7 +20,7 @@
         {
             SurfaceLines = new ObservableList<RingtoetsPipingSurfaceLine>();
             SoilProfiles = Enumerable.Empty<PipingSoilProfile>();
-            PipingData = new PipingData();
+            Calculations = new List<PipingData> { new PipingData() };
         }
 
         /// <summary>
@@ -29,14 +29,14 @@
         public IEnumerable<RingtoetsPipingSurfaceLine> SurfaceLines { get; private set; }
 
         /// <summary>
-        /// Gets the <see cref="PipingData"/>, which contains input and output of a piping calculation.
+        /// Gets the available profiles within the scope of the piping failure mechanism.
         /// </summary>
-        public PipingData PipingData { get; private set; }
+        public IEnumerable SoilProfiles { get; private set; }
 
         /// <summary>
-        /// Gets the available profiles within the scope of the piping failure mechanism.
+        /// Gets all available piping calculations.
         /// </summary>
-        public IEnumerable SoilProfiles { get; private set; }
+        public ICollection<PipingData> Calculations { get; private set; }
 
         public void Attach(IObserver observer)
         {
Index: src/Plugins/Ringtoets/Piping/src/Ringtoets.Piping.Forms/NodePresenters/PipingFailureMechanismNodePresenter.cs
===================================================================
diff -u -r300a33d9acf653458b834b296becbf9ae552de8e -rdf0cc3cc798c0d57715d9dbe78b71387066913b5
--- src/Plugins/Ringtoets/Piping/src/Ringtoets.Piping.Forms/NodePresenters/PipingFailureMechanismNodePresenter.cs	(.../PipingFailureMechanismNodePresenter.cs)	(revision 300a33d9acf653458b834b296becbf9ae552de8e)
+++ src/Plugins/Ringtoets/Piping/src/Ringtoets.Piping.Forms/NodePresenters/PipingFailureMechanismNodePresenter.cs	(.../PipingFailureMechanismNodePresenter.cs)	(revision df0cc3cc798c0d57715d9dbe78b71387066913b5)
@@ -6,7 +6,7 @@
 using DelftTools.Utils.Collections;
 
 using Ringtoets.Piping.Data;
-
+using Ringtoets.Piping.Forms.Extensions;
 using Ringtoets.Piping.Forms.PresentationObjects;
 using Ringtoets.Piping.Forms.Properties;
 
@@ -36,11 +36,11 @@
             yield return failureMechanism.SoilProfiles;
             yield return failureMechanism.SurfaceLines;
 
-            if (failureMechanism.PipingData != null)
+            foreach (var calculation in failureMechanism.Calculations)
             {
                 yield return new PipingCalculationInputs
                 {
-                    PipingData = failureMechanism.PipingData, 
+                    PipingData = calculation,
                     AvailablePipingSurfaceLines = failureMechanism.SurfaceLines
                 };
             }
@@ -84,7 +84,17 @@
 
         public ContextMenuStrip GetContextMenu(ITreeNode sender, object nodeData)
         {
-            return null;
+            var rootMenu = new ContextMenuStrip();
+
+            rootMenu.AddMenuItem("Berekening toevoegen", "Voeg een nieuwe piping berekening toe aan het faalmechanisme.",
+                Resources.PipingIcon, (o, args) =>
+                {
+                    var failureMechanism = (PipingFailureMechanism)nodeData;
+                    failureMechanism.Calculations.Add(new PipingData());
+                    failureMechanism.NotifyObservers();
+                });
+
+            return rootMenu;
         }
 
         public void OnPropertyChanged(object sender, ITreeNode node, PropertyChangedEventArgs e) {}
Index: src/Plugins/Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingFailureMechanismTest.cs
===================================================================
diff -u -r300a33d9acf653458b834b296becbf9ae552de8e -rdf0cc3cc798c0d57715d9dbe78b71387066913b5
--- src/Plugins/Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingFailureMechanismTest.cs	(.../PipingFailureMechanismTest.cs)	(revision 300a33d9acf653458b834b296becbf9ae552de8e)
+++ src/Plugins/Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingFailureMechanismTest.cs	(.../PipingFailureMechanismTest.cs)	(revision df0cc3cc798c0d57715d9dbe78b71387066913b5)
@@ -2,8 +2,6 @@
 using NUnit.Framework;
 using Rhino.Mocks;
 
-using Ringtoets.Piping.Data;
-
 namespace Ringtoets.Piping.Data.Test
 {
     [TestFixture]
@@ -27,7 +25,7 @@
             CollectionAssert.IsEmpty(piping.SurfaceLines);
             Assert.IsInstanceOf<ObservableList<RingtoetsPipingSurfaceLine>>(piping.SurfaceLines);
             CollectionAssert.IsEmpty(piping.SoilProfiles);
-            Assert.IsNotNull(piping.PipingData);
+            Assert.AreEqual(1, piping.Calculations.Count);
         }
 
         [Test]
Index: src/Plugins/Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/NodePresenters/PipingFailureMechanismNodePresenterTest.cs
===================================================================
diff -u -r300a33d9acf653458b834b296becbf9ae552de8e -rdf0cc3cc798c0d57715d9dbe78b71387066913b5
--- src/Plugins/Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/NodePresenters/PipingFailureMechanismNodePresenterTest.cs	(.../PipingFailureMechanismNodePresenterTest.cs)	(revision 300a33d9acf653458b834b296becbf9ae552de8e)
+++ src/Plugins/Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/NodePresenters/PipingFailureMechanismNodePresenterTest.cs	(.../PipingFailureMechanismNodePresenterTest.cs)	(revision df0cc3cc798c0d57715d9dbe78b71387066913b5)
@@ -2,6 +2,7 @@
 using System.ComponentModel;
 using System.Linq;
 using DelftTools.Controls;
+using DelftTools.Shell.Core;
 using DelftTools.Utils.Collections;
 using NUnit.Framework;
 using Rhino.Mocks;
@@ -61,17 +62,25 @@
             var nodePresenter = new PipingFailureMechanismNodePresenter();
 
             var pipingFailureMechanism = new PipingFailureMechanism();
+            pipingFailureMechanism.Calculations.Add(new PipingData());
+            pipingFailureMechanism.Calculations.Add(new PipingData());
 
             // Call
             var children = nodePresenter.GetChildNodeObjects(pipingFailureMechanism, nodeMock).OfType<object>().ToArray();
 
             // Assert
-            Assert.AreEqual(3, children.Length);
+            Assert.AreEqual(5, children.Length);
             Assert.AreSame(pipingFailureMechanism.SoilProfiles, children[0]);
             Assert.AreSame(pipingFailureMechanism.SurfaceLines, children[1]);
-            var pipingCalculationInputsObject = (PipingCalculationInputs)children[2];
-            Assert.AreSame(pipingFailureMechanism.PipingData, pipingCalculationInputsObject.PipingData);
-            Assert.AreSame(pipingFailureMechanism.SurfaceLines, pipingCalculationInputsObject.AvailablePipingSurfaceLines);
+            var pipingCalculationInputsChildObjects = children.Skip(2)
+                                                              .Take(pipingFailureMechanism.Calculations.Count)
+                                                              .Cast<PipingCalculationInputs>()
+                                                              .ToArray();
+            CollectionAssert.AreEqual(pipingFailureMechanism.Calculations, pipingCalculationInputsChildObjects.Select(pci => pci.PipingData).ToArray());
+            foreach (var pipingData in pipingCalculationInputsChildObjects)
+            {
+                Assert.AreSame(pipingFailureMechanism.SurfaceLines, pipingData.AvailablePipingSurfaceLines);
+            }
             mocks.VerifyAll(); // Expect no calls on tree node
         }
 
@@ -258,11 +267,43 @@
             var contextMenu = nodePresenter.GetContextMenu(nodeMock, dataMock);
 
             // Assert
-            Assert.IsNull(contextMenu);
+            Assert.AreEqual(1, contextMenu.Items.Count);
+            var addCalculationItem = contextMenu.Items[0];
+            Assert.AreEqual("Berekening toevoegen", addCalculationItem.Text);
+            Assert.AreEqual("Voeg een nieuwe piping berekening toe aan het faalmechanisme.", addCalculationItem.ToolTipText);
+            Assert.AreEqual(16, addCalculationItem.Image.Width);
+            Assert.AreEqual(16, addCalculationItem.Image.Height);
             mocks.VerifyAll(); // Expect no calls on arguments
         }
 
         [Test]
+        public void GetContextMenu_ClickOnAddCalculationItem_NewPipingDataInstanceAddedToCalculationAndNotifyObservers()
+        {
+            // Setup
+            var mocks = new MockRepository();
+            var nodeMock = mocks.StrictMock<ITreeNode>();
+            var observerMock = mocks.StrictMock<IObserver>();
+            observerMock.Expect(o => o.UpdateObserver());
+            mocks.ReplayAll();
+
+            var failureMechanism = new PipingFailureMechanism();
+            failureMechanism.Attach(observerMock);
+            var nodePresenter = new PipingFailureMechanismNodePresenter();
+
+            // Precondition
+            Assert.AreEqual(1, failureMechanism.Calculations.Count);
+
+            // Call
+            var contextMenu = nodePresenter.GetContextMenu(nodeMock, failureMechanism);
+            var addCalculationItem = contextMenu.Items[0];
+            addCalculationItem.PerformClick();
+
+            // Assert
+            Assert.AreEqual(2, failureMechanism.Calculations.Count);
+            mocks.VerifyAll();
+        }
+
+        [Test]
         public void OnPropertyChange_Always_DoNothing()
         {
             // Setup