Index: Riskeer/Piping/src/Riskeer.Piping.Data/PipingCalculation.cs
===================================================================
diff -u -rdf1942940ece42a98d022f8c4a8bd873274462fc -r908cf6f1b1d313f7eb83ba544d26056c8f34cab1
--- Riskeer/Piping/src/Riskeer.Piping.Data/PipingCalculation.cs	(.../PipingCalculation.cs)	(revision df1942940ece42a98d022f8c4a8bd873274462fc)
+++ Riskeer/Piping/src/Riskeer.Piping.Data/PipingCalculation.cs	(.../PipingCalculation.cs)	(revision 908cf6f1b1d313f7eb83ba544d26056c8f34cab1)
@@ -55,39 +55,19 @@
         }
 
         /// <summary>
-        /// Gets or sets the results of the piping calculation.
-        /// </summary>
-        public TPipingOutput Output { get; set; }
-
-        /// <summary>
         /// Gets the input parameters to perform the piping calculation with.
         /// </summary>
         public TPipingInput InputParameters { get; private set; }
 
         public string Name { get; set; }
 
-        public bool ShouldCalculate
-        {
-            get
-            {
-                return !HasOutput;
-            }
-        }
+        public bool ShouldCalculate => !HasOutput;
 
-        public bool HasOutput
-        {
-            get
-            {
-                return Output != null;
-            }
-        }
+        public abstract bool HasOutput { get; }
 
         public Comment Comments { get; private set; }
 
-        public void ClearOutput()
-        {
-            Output = null;
-        }
+        public abstract void ClearOutput();
 
         public override object Clone()
         {
@@ -96,11 +76,6 @@
             clone.Comments = (Comment) Comments.Clone();
             clone.InputParameters = (TPipingInput) InputParameters.Clone();
 
-            if (Output != null)
-            {
-                clone.Output = (TPipingOutput) Output.Clone();
-            }
-
             return clone;
         }
     }
Index: Riskeer/Piping/src/Riskeer.Piping.Data/SemiProbabilistic/SemiProbabilisticPipingCalculation.cs
===================================================================
diff -u -rd2d48d2bd3050679db76ec126d31b8f9d9546395 -r908cf6f1b1d313f7eb83ba544d26056c8f34cab1
--- Riskeer/Piping/src/Riskeer.Piping.Data/SemiProbabilistic/SemiProbabilisticPipingCalculation.cs	(.../SemiProbabilisticPipingCalculation.cs)	(revision d2d48d2bd3050679db76ec126d31b8f9d9546395)
+++ Riskeer/Piping/src/Riskeer.Piping.Data/SemiProbabilistic/SemiProbabilisticPipingCalculation.cs	(.../SemiProbabilisticPipingCalculation.cs)	(revision 908cf6f1b1d313f7eb83ba544d26056c8f34cab1)
@@ -36,5 +36,29 @@
         /// <exception cref="ArgumentNullException">Thrown when <paramref name="generalInputParameters"/>
         /// is <c>null</c>.</exception>
         public SemiProbabilisticPipingCalculation(GeneralPipingInput generalInputParameters) : base(new SemiProbabilisticPipingInput(generalInputParameters)) {}
+
+        public override bool HasOutput => Output != null;
+
+        /// <summary>
+        /// Gets or sets the results of the piping calculation.
+        /// </summary>
+        public PipingOutput Output { get; set; }
+
+        public override void ClearOutput()
+        {
+            Output = null;
+        }
+
+        public override object Clone()
+        {
+            var clone = (SemiProbabilisticPipingCalculation) base.Clone();
+
+            if (Output != null)
+            {
+                clone.Output = (PipingOutput) Output.Clone();
+            }
+
+            return clone;
+        }
     }
 }
\ No newline at end of file