Index: Riskeer/Piping/src/Riskeer.Piping.Data/Probabilistic/ProbabilisticPipingOutput.cs
===================================================================
diff -u -rb73588e5f0c90398c590383b9e6996f996c19735 -rfc485da07b4e72ca041d014eef9a280446d2a751
--- Riskeer/Piping/src/Riskeer.Piping.Data/Probabilistic/ProbabilisticPipingOutput.cs	(.../ProbabilisticPipingOutput.cs)	(revision b73588e5f0c90398c590383b9e6996f996c19735)
+++ Riskeer/Piping/src/Riskeer.Piping.Data/Probabilistic/ProbabilisticPipingOutput.cs	(.../ProbabilisticPipingOutput.cs)	(revision fc485da07b4e72ca041d014eef9a280446d2a751)
@@ -45,11 +45,28 @@
         /// <summary>
         /// Gets the result of the sub-calculation that takes into account the section length.
         /// </summary>
-        public PartialProbabilisticPipingOutput ResultWithLength { get; }
+        public PartialProbabilisticPipingOutput ResultWithLength { get; private set; }
 
         /// <summary>
         /// Gets the result of the sub-calculation that doesn't take into account the section length.
         /// </summary>
-        public PartialProbabilisticPipingOutput ResultWithoutLength { get; }
+        public PartialProbabilisticPipingOutput ResultWithoutLength { get; private set; }
+        
+        public override object Clone()
+        {
+            var clone = (ProbabilisticPipingOutput) base.Clone();
+
+            if (ResultWithLength != null)
+            {
+                clone.ResultWithLength = (PartialProbabilisticPipingOutput) ResultWithLength.Clone();
+            }
+
+            if (ResultWithoutLength != null)
+            {
+                clone.ResultWithoutLength = (PartialProbabilisticPipingOutput) ResultWithoutLength.Clone();
+            }
+            
+            return clone;
+        }
     }
 }
\ No newline at end of file
Index: Riskeer/Piping/test/Riskeer.Piping.Data.Test/Probabilistic/ProbabilisticPipingOutputTest.cs
===================================================================
diff -u -rb73588e5f0c90398c590383b9e6996f996c19735 -rfc485da07b4e72ca041d014eef9a280446d2a751
--- Riskeer/Piping/test/Riskeer.Piping.Data.Test/Probabilistic/ProbabilisticPipingOutputTest.cs	(.../ProbabilisticPipingOutputTest.cs)	(revision b73588e5f0c90398c590383b9e6996f996c19735)
+++ Riskeer/Piping/test/Riskeer.Piping.Data.Test/Probabilistic/ProbabilisticPipingOutputTest.cs	(.../ProbabilisticPipingOutputTest.cs)	(revision fc485da07b4e72ca041d014eef9a280446d2a751)
@@ -50,9 +50,48 @@
         }
 
         [Test]
-        public void Clone_Always_ReturnNewInstanceWithCopiedValues()
+        public void Clone_NoPropertiesSet_ReturnNewInstanceWithCopiedValues()
         {
             // Setup
+            var original = new ProbabilisticPipingOutput(null, null);
+
+            // Call
+            object clone = original.Clone();
+
+            // Assert
+            CoreCloneAssert.AreObjectClones(original, clone, PipingCloneAssert.AreClones);
+        }
+
+        [Test]
+        public void Clone_OnlyOutputWithLengthSet_ReturnNewInstanceWithCopiedValues()
+        {
+            // Setup
+            var original = new ProbabilisticPipingOutput(PipingTestDataGenerator.GetRandomPartialProbabilisticPipingOutput(new TestGeneralResultFaultTreeIllustrationPoint()), null);
+
+            // Call
+            object clone = original.Clone();
+
+            // Assert
+            CoreCloneAssert.AreObjectClones(original, clone, PipingCloneAssert.AreClones);
+        }
+
+        [Test]
+        public void Clone_OnlyOutputWithoutLengthSet_ReturnNewInstanceWithCopiedValues()
+        {
+            // Setup
+            var original = new ProbabilisticPipingOutput(null, PipingTestDataGenerator.GetRandomPartialProbabilisticPipingOutput(new TestGeneralResultFaultTreeIllustrationPoint()));
+
+            // Call
+            object clone = original.Clone();
+
+            // Assert
+            CoreCloneAssert.AreObjectClones(original, clone, PipingCloneAssert.AreClones);
+        }
+
+        [Test]
+        public void Clone_AllPropertiesSet_ReturnNewInstanceWithCopiedValues()
+        {
+            // Setup
             ProbabilisticPipingOutput original = PipingTestDataGenerator.GetRandomProbabilisticPipingOutput();
 
             // Call
Index: Riskeer/Piping/test/Riskeer.Piping.Data.TestUtil/PipingCloneAssert.cs
===================================================================
diff -u -rbf7a895f63e091ac3a9f225d082e9b5cd6556b6d -rfc485da07b4e72ca041d014eef9a280446d2a751
--- Riskeer/Piping/test/Riskeer.Piping.Data.TestUtil/PipingCloneAssert.cs	(.../PipingCloneAssert.cs)	(revision bf7a895f63e091ac3a9f225d082e9b5cd6556b6d)
+++ Riskeer/Piping/test/Riskeer.Piping.Data.TestUtil/PipingCloneAssert.cs	(.../PipingCloneAssert.cs)	(revision fc485da07b4e72ca041d014eef9a280446d2a751)
@@ -63,8 +63,8 @@
         /// <paramref name="clone"/> are not clones.</exception>
         public static void AreClones(ProbabilisticPipingOutput original, ProbabilisticPipingOutput clone)
         {
-            AreClones(original.ResultWithLength, clone.ResultWithLength);
-            AreClones(original.ResultWithoutLength, clone.ResultWithoutLength);
+            CoreCloneAssert.AreObjectClones(original.ResultWithLength, clone.ResultWithLength, AreClones);
+            CoreCloneAssert.AreObjectClones(original.ResultWithoutLength, clone.ResultWithoutLength, AreClones);
         }
 
         /// <summary>