Index: Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil/Kernels/Assessments/FailureMechanismSectionAssessmentAssemblyKernelStub.cs
===================================================================
diff -u -rfc7fbe9882364e7caae2093c378d3cacd8858d00 -re7a4858c35baedd9d9dbd6254687945f3f04be7a
--- Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil/Kernels/Assessments/FailureMechanismSectionAssessmentAssemblyKernelStub.cs	(.../FailureMechanismSectionAssessmentAssemblyKernelStub.cs)	(revision fc7fbe9882364e7caae2093c378d3cacd8858d00)
+++ Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil/Kernels/Assessments/FailureMechanismSectionAssessmentAssemblyKernelStub.cs	(.../FailureMechanismSectionAssessmentAssemblyKernelStub.cs)	(revision e7a4858c35baedd9d9dbd6254687945f3f04be7a)
@@ -39,6 +39,11 @@
         public SimpleCalculationResult? SimpleAssessmentFailureMechanismsInput { get; private set; }
 
         /// <summary>
+        /// Gets the input used in <see cref="SimpleAssessmentDirectFailureMechanisms(SimpleCalculationResultValidityOnly)"/>.
+        /// </summary>
+        public SimpleCalculationResultValidityOnly? SimpleAssessmentFailureMechanismsValidityOnlyInput { get; private set; }
+
+        /// <summary>
         /// Gets a value indicating whether a calculation was called or not.
         /// </summary>
         public bool Calculated { get; private set; }
@@ -72,7 +77,14 @@
 
         public CalculationOutput<FailureMechanismSectionAssemblyCategoryResult> SimpleAssessmentDirectFailureMechanisms(SimpleCalculationResultValidityOnly result)
         {
-            throw new NotImplementedException();
+            if (ThrowExceptionOnCalculate)
+            {
+                throw new Exception("Message", new Exception());
+            }
+
+            SimpleAssessmentFailureMechanismsValidityOnlyInput = result;
+            Calculated = true;
+            return FailureMechanismSectionAssemblyCategoryResult;
         }
 
         public CalculationOutput<FailureMechanismSectionCategoryGroup> DetailedAssessmentDirectFailureMechanisms(DetailedCalculationResult result)