Index: Riskeer/Common/src/Riskeer.Common.Data/Helpers/CalculationScenarioHelper.cs
===================================================================
diff -u -r0eed9aa596fb1a96e3ea45636aa5ee870a4bb48c -rf68e9405a0fd41124823662da365309faec0f988
--- Riskeer/Common/src/Riskeer.Common.Data/Helpers/CalculationScenarioHelper.cs	(.../CalculationScenarioHelper.cs)	(revision 0eed9aa596fb1a96e3ea45636aa5ee870a4bb48c)
+++ Riskeer/Common/src/Riskeer.Common.Data/Helpers/CalculationScenarioHelper.cs	(.../CalculationScenarioHelper.cs)	(revision f68e9405a0fd41124823662da365309faec0f988)
@@ -72,5 +72,20 @@
 
             return (RoundedDouble) calculationScenarios.Aggregate<T, double>(0, (current, calculationScenario) => current + calculationScenario.Contribution);
         }
+        
+        /// <summary>
+        /// Gets whether the calculation scenarios are valid.
+        /// </summary>
+        /// <param name="relevantScenarios"></param>
+        /// <typeparam name="T">The type of the calculation scenarios.</typeparam>
+        /// <returns><c>true</c> when there are calculation scenarios,
+        /// they all have output and the total contribution is 1.0; <c>false</c> otherwise.</returns>
+        public static bool ScenariosAreValid<T>(T[] relevantScenarios)
+            where T : ICalculationScenario
+        {
+            return relevantScenarios.Any()
+                   && relevantScenarios.All(s => s.HasOutput)
+                   && Math.Abs(GetTotalContribution(relevantScenarios) - 1.0) <= 1e-6;
+        }
     }
 }
\ No newline at end of file
Index: Riskeer/Common/test/Riskeer.Common.Data.Test/Helpers/CalculationScenarioHelperTest.cs
===================================================================
diff -u -ra72a0c1fefeb2474c6838b6ffd504a8a7b6ac5a0 -rf68e9405a0fd41124823662da365309faec0f988
--- Riskeer/Common/test/Riskeer.Common.Data.Test/Helpers/CalculationScenarioHelperTest.cs	(.../CalculationScenarioHelperTest.cs)	(revision a72a0c1fefeb2474c6838b6ffd504a8a7b6ac5a0)
+++ Riskeer/Common/test/Riskeer.Common.Data.Test/Helpers/CalculationScenarioHelperTest.cs	(.../CalculationScenarioHelperTest.cs)	(revision f68e9405a0fd41124823662da365309faec0f988)
@@ -102,5 +102,100 @@
             RoundedDouble expectedTotalContribution = calculationScenario1.Contribution + calculationScenario2.Contribution;
             Assert.AreEqual(expectedTotalContribution, totalContribution);
         }
+
+        [Test]
+        public void ScenariosAreValid_ScenariosEmpty_ReturnsFalse()
+        {
+            // Call
+            bool valid = CalculationScenarioHelper.ScenariosAreValid(Array.Empty<ICalculationScenario>());
+            
+            // Assert
+            Assert.IsFalse(valid);
+        }
+
+        [Test]
+        public void ScenariosAreValid_ScenariosWithoutOutput_ReturnsFalse()
+        {
+            // Setup
+            var calculationScenario1 = new TestCalculationScenario
+            {
+                Contribution = (RoundedDouble) 0.4323,
+                Output = new object()
+            };
+            var calculationScenario2 = new TestCalculationScenario
+            {
+                Contribution = (RoundedDouble) 0.1226
+            };
+            
+            // Call
+            bool valid = CalculationScenarioHelper.ScenariosAreValid(new[]
+            {
+                calculationScenario1,
+                calculationScenario2
+            });
+            
+            // Assert
+            Assert.IsFalse(valid);
+        }
+
+        [Test]
+        [TestCase(0.4323, 0.1226)]
+        [TestCase(0.9000, 0.9000)]
+        [TestCase(1, 0.0001)]
+        [TestCase(0.0001, 0.9998)]
+        public void ScenariosAreValid_ScenariosContributionNotOne_ReturnsFalse(double scenarioContribution1,
+                                                                               double scenarioContribution2)
+        {
+            // Setup
+            var calculationScenario1 = new TestCalculationScenario
+            {
+                Contribution = (RoundedDouble) scenarioContribution1,
+                Output = new object()
+            };
+            var calculationScenario2 = new TestCalculationScenario
+            {
+                Contribution = (RoundedDouble) scenarioContribution2,
+                Output = new object()
+            };
+            
+            // Call
+            bool valid = CalculationScenarioHelper.ScenariosAreValid(new[]
+            {
+                calculationScenario1,
+                calculationScenario2
+            });
+            
+            // Assert
+            Assert.IsFalse(valid);
+        }
+
+        [Test]
+        [TestCase(1, 0)]
+        [TestCase(0.0001, 0.9999)]
+        public void ScenariosAreValid_ScenariosWithOutputAndContributionOne_ReturnsTrue(double scenarioContribution1,
+                                                                                        double scenarioContribution2)
+        {
+            // Setup
+            var calculationScenario1 = new TestCalculationScenario
+            {
+                Contribution = (RoundedDouble) scenarioContribution1,
+                Output = new object()
+            };
+            var calculationScenario2 = new TestCalculationScenario
+            {
+                Contribution = (RoundedDouble) scenarioContribution2,
+                Output = new object()
+            };
+            
+            // Call
+            bool valid = CalculationScenarioHelper.ScenariosAreValid(new[]
+            {
+                calculationScenario1,
+                calculationScenario2
+            });
+            
+            // Assert
+            Assert.IsTrue(valid);
+        }
     }
 }
\ No newline at end of file
Index: Riskeer/Piping/src/Riskeer.Piping.Data/PipingFailureMechanismSectionResultInitialFailureMechanismResultExtensions.cs
===================================================================
diff -u -re2eb901c9bfce4975c5050dbbea4065dfdb41871 -rf68e9405a0fd41124823662da365309faec0f988
--- Riskeer/Piping/src/Riskeer.Piping.Data/PipingFailureMechanismSectionResultInitialFailureMechanismResultExtensions.cs	(.../PipingFailureMechanismSectionResultInitialFailureMechanismResultExtensions.cs)	(revision e2eb901c9bfce4975c5050dbbea4065dfdb41871)
+++ Riskeer/Piping/src/Riskeer.Piping.Data/PipingFailureMechanismSectionResultInitialFailureMechanismResultExtensions.cs	(.../PipingFailureMechanismSectionResultInitialFailureMechanismResultExtensions.cs)	(revision f68e9405a0fd41124823662da365309faec0f988)
@@ -31,7 +31,8 @@
 namespace Riskeer.Piping.Data
 {
     /// <summary>
-    /// Extension methods for obtaining initial failure mechanism result probabilities from output for an assessment of the piping failure mechanism.
+    /// Extension methods for obtaining initial failure mechanism result probabilities
+    /// from output for an assessment of the piping failure mechanism.
     /// </summary>
     public static class PipingFailureMechanismSectionResultInitialFailureMechanismResultExtensions
     {
@@ -69,7 +70,7 @@
                                                                                           (scenario, lineSegments) => scenario.IsSurfaceLineIntersectionWithReferenceLineInSection(lineSegments))
                                                                                       .ToArray();
 
-            return ScenariosAreValid(relevantScenarios)
+            return CalculationScenarioHelper.ScenariosAreValid(relevantScenarios)
                        ? relevantScenarios.Sum(scenario => StatisticsConverter.ReliabilityToProbability(getOutputFunc(scenario).Reliability) * (double) scenario.Contribution)
                        : double.NaN;
         }
@@ -103,7 +104,7 @@
                                                                                               (scenario, lineSegments) => scenario.IsSurfaceLineIntersectionWithReferenceLineInSection(lineSegments))
                                                                                           .ToArray();
 
-            if (!ScenariosAreValid(relevantScenarios))
+            if (!CalculationScenarioHelper.ScenariosAreValid(relevantScenarios))
             {
                 return double.NaN;
             }
@@ -118,13 +119,5 @@
 
             return totalInitialFailureMechanismResult;
         }
-
-        private static bool ScenariosAreValid<T>(T[] relevantScenarios)
-            where T : IPipingCalculationScenario<PipingInput>
-        {
-            return relevantScenarios.Any()
-                   && relevantScenarios.All(s => s.HasOutput)
-                   && Math.Abs(CalculationScenarioHelper.GetTotalContribution(relevantScenarios) - 1.0) <= 1e-6;
-        }
     }
 }
\ No newline at end of file