Index: Riskeer/Piping/src/Riskeer.Piping.Data/IPipingCalculation.cs
===================================================================
diff -u -r56b853f016b53da306c8946e7709030b9b08e15f -r210f00931ebf34d8457c9191f8c743a4206b78a8
--- Riskeer/Piping/src/Riskeer.Piping.Data/IPipingCalculation.cs	(.../IPipingCalculation.cs)	(revision 56b853f016b53da306c8946e7709030b9b08e15f)
+++ Riskeer/Piping/src/Riskeer.Piping.Data/IPipingCalculation.cs	(.../IPipingCalculation.cs)	(revision 210f00931ebf34d8457c9191f8c743a4206b78a8)
@@ -30,5 +30,11 @@
     /// <typeparam name="TPipingOutput">The type of calculation output.</typeparam>
     public interface IPipingCalculation<out TPipingInput, out TPipingOutput> : ICalculation<TPipingInput>
         where TPipingInput : PipingInput
-        where TPipingOutput : PipingOutput {}
+        where TPipingOutput : PipingOutput
+    {
+        /// <summary>
+        /// Gets the results of the piping calculation.
+        /// </summary>
+        TPipingOutput Output { get; }
+    }
 }
\ No newline at end of file
Index: Riskeer/Piping/test/Riskeer.Piping.Data.TestUtil/PipingCloneAssert.cs
===================================================================
diff -u -rb35f3918dba57bcc05bf62e492079789ed9dd64a -r210f00931ebf34d8457c9191f8c743a4206b78a8
--- Riskeer/Piping/test/Riskeer.Piping.Data.TestUtil/PipingCloneAssert.cs	(.../PipingCloneAssert.cs)	(revision b35f3918dba57bcc05bf62e492079789ed9dd64a)
+++ Riskeer/Piping/test/Riskeer.Piping.Data.TestUtil/PipingCloneAssert.cs	(.../PipingCloneAssert.cs)	(revision 210f00931ebf34d8457c9191f8c743a4206b78a8)
@@ -82,7 +82,7 @@
         /// <param name="clone">The cloned object.</param>
         /// <exception cref="AssertionException">Thrown when <paramref name="original"/> and
         /// <paramref name="clone"/> are not clones.</exception>
-        public static void AreClones(PipingCalculation<PipingInput, PipingOutput> original, PipingCalculation<PipingInput, PipingOutput> clone)
+        public static void AreClones(IPipingCalculation<PipingInput, PipingOutput> original, IPipingCalculation<PipingInput, PipingOutput> clone)
         {
             Assert.AreEqual(original.Name, clone.Name);
             CoreCloneAssert.AreObjectClones(original.Comments, clone.Comments, CommonCloneAssert.AreClones);
@@ -100,7 +100,7 @@
         /// <paramref name="clone"/> are not clones.</exception>
         public static void AreClones(PipingCalculationScenario original, PipingCalculationScenario clone)
         {
-            AreClones((PipingCalculation<PipingInput, PipingOutput>) original, clone);
+            AreClones((IPipingCalculation<PipingInput, PipingOutput>) original, clone);
             Assert.AreEqual(original.Contribution, clone.Contribution);
             Assert.AreEqual(original.IsRelevant, clone.IsRelevant);
         }