Index: Ringtoets/Integration/src/Ringtoets.Integration.Forms/PropertyClasses/StandAlone/MacroStabilityOutwardsFailureMechanismProperties.cs
===================================================================
diff -u -rba2c38d1315dda29a2bd0005138530b2aeb10f1f -r419f4e155d67de33512a25a7b95e2c2830429eeb
--- Ringtoets/Integration/src/Ringtoets.Integration.Forms/PropertyClasses/StandAlone/MacroStabilityOutwardsFailureMechanismProperties.cs	(.../MacroStabilityOutwardsFailureMechanismProperties.cs)	(revision ba2c38d1315dda29a2bd0005138530b2aeb10f1f)
+++ Ringtoets/Integration/src/Ringtoets.Integration.Forms/PropertyClasses/StandAlone/MacroStabilityOutwardsFailureMechanismProperties.cs	(.../MacroStabilityOutwardsFailureMechanismProperties.cs)	(revision 419f4e155d67de33512a25a7b95e2c2830429eeb)
@@ -64,7 +64,8 @@
 
         private bool ShouldHidePropertyWhenFailureMechanismIrrelevant(string propertyName)
         {
-            return nameof(A).Equals(propertyName)
+            return nameof(Contribution).Equals(propertyName)
+                   || nameof(A).Equals(propertyName)
                    || nameof(B).Equals(propertyName)
                    || nameof(SectionLength).Equals(propertyName)
                    || nameof(N).Equals(propertyName);
@@ -96,8 +97,21 @@
             }
         }
 
+        [DynamicVisible]
         [PropertyOrder(3)]
         [ResourcesCategory(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.Categories_General))]
+        [ResourcesDisplayName(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.FailureMechanism_Contribution_DisplayName))]
+        [ResourcesDescription(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.FailureMechanism_Contribution_Description))]
+        public double Contribution
+        {
+            get
+            {
+                return data.Contribution;
+            }
+        }
+
+        [PropertyOrder(4)]
+        [ResourcesCategory(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.Categories_General))]
         [ResourcesDisplayName(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.FailureMechanism_IsRelevant_DisplayName))]
         [ResourcesDescription(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.FailureMechanism_IsRelevant_Description))]
         public bool IsRelevant
@@ -113,7 +127,7 @@
         #region Length effect parameters
 
         [DynamicVisible]
-        [PropertyOrder(4)]
+        [PropertyOrder(5)]
         [ResourcesCategory(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.Categories_LengthEffect))]
         [ResourcesDisplayName(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.FailureMechanism_ProbabilityAssessmentInput_A_DisplayName))]
         [ResourcesDescription(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.FailureMechanism_ProbabilityAssessmentInput_A_Description))]
@@ -131,7 +145,7 @@
         }
 
         [DynamicVisible]
-        [PropertyOrder(5)]
+        [PropertyOrder(6)]
         [ResourcesCategory(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.Categories_LengthEffect))]
         [ResourcesDisplayName(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.FailureMechanism_ProbabilityAssessmentInput_B_DisplayName))]
         [ResourcesDescription(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.FailureMechanism_ProbabilityAssessmentInput_B_Description))]
@@ -144,7 +158,7 @@
         }
 
         [DynamicVisible]
-        [PropertyOrder(6)]
+        [PropertyOrder(7)]
         [ResourcesCategory(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.Categories_LengthEffect))]
         [ResourcesDisplayName(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.ReferenceLine_Length_Rounded_DisplayName))]
         [ResourcesDescription(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.ReferenceLine_Length_Rounded_Description))]
@@ -157,7 +171,7 @@
         }
 
         [DynamicVisible]
-        [PropertyOrder(7)]
+        [PropertyOrder(8)]
         [ResourcesCategory(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.Categories_LengthEffect))]
         [ResourcesDisplayName(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.FailureMechanism_N_Rounded_DisplayName))]
         [ResourcesDescription(typeof(RingtoetsCommonFormsResources), nameof(RingtoetsCommonFormsResources.FailureMechanism_N_Rounded_Description))]
Index: Ringtoets/Integration/test/Ringtoets.Integration.Forms.Test/PropertyClasses/StandAlone/MacroStabilityOutwardsFailureMechanismPropertiesTest.cs
===================================================================
diff -u -r9f509058d44189f44b16a8da06a60751b17c86c3 -r419f4e155d67de33512a25a7b95e2c2830429eeb
--- Ringtoets/Integration/test/Ringtoets.Integration.Forms.Test/PropertyClasses/StandAlone/MacroStabilityOutwardsFailureMechanismPropertiesTest.cs	(.../MacroStabilityOutwardsFailureMechanismPropertiesTest.cs)	(revision 9f509058d44189f44b16a8da06a60751b17c86c3)
+++ Ringtoets/Integration/test/Ringtoets.Integration.Forms.Test/PropertyClasses/StandAlone/MacroStabilityOutwardsFailureMechanismPropertiesTest.cs	(.../MacroStabilityOutwardsFailureMechanismPropertiesTest.cs)	(revision 419f4e155d67de33512a25a7b95e2c2830429eeb)
@@ -65,6 +65,7 @@
             Assert.IsInstanceOf<ObjectProperties<MacroStabilityOutwardsFailureMechanism>>(properties);
             Assert.AreEqual(failureMechanism.Name, properties.Name);
             Assert.AreEqual(failureMechanism.Code, properties.Code);
+            Assert.AreEqual(failureMechanism.Contribution, properties.Contribution);
             Assert.AreEqual(isRelevant, properties.IsRelevant);
 
             MacroStabilityOutwardsProbabilityAssessmentInput probabilityAssessmentInput = failureMechanism.MacroStabilityOutwardsProbabilityAssessmentInput;
@@ -94,7 +95,7 @@
 
             // Assert
             PropertyDescriptorCollection dynamicProperties = PropertiesTestHelper.GetAllVisiblePropertyDescriptors(properties);
-            Assert.AreEqual(7, dynamicProperties.Count);
+            Assert.AreEqual(8, dynamicProperties.Count);
 
             const string generalCategory = "Algemeen";
             const string lengthEffectCategory = "Lengte-effect parameters";
@@ -113,34 +114,41 @@
                                                                             "Het label van het toetsspoor.",
                                                                             true);
 
-            PropertyDescriptor isRelevantProperty = dynamicProperties[2];
+            PropertyDescriptor contributionProperty = dynamicProperties[2];
+            PropertiesTestHelper.AssertRequiredPropertyDescriptorProperties(contributionProperty,
+                                                                            generalCategory,
+                                                                            "Faalkansbijdrage [%]",
+                                                                            "Procentuele bijdrage van dit toetsspoor aan de totale overstromingskans van het traject.",
+                                                                            true);
+
+            PropertyDescriptor isRelevantProperty = dynamicProperties[3];
             PropertiesTestHelper.AssertRequiredPropertyDescriptorProperties(isRelevantProperty,
                                                                             generalCategory,
                                                                             "Is relevant",
                                                                             "Geeft aan of dit toetsspoor relevant is of niet.",
                                                                             true);
 
-            PropertyDescriptor aProperty = dynamicProperties[3];
+            PropertyDescriptor aProperty = dynamicProperties[4];
             PropertiesTestHelper.AssertRequiredPropertyDescriptorProperties(aProperty,
                                                                             lengthEffectCategory,
                                                                             "a [-]",
                                                                             "De parameter 'a' die gebruikt wordt voor het lengte-effect in berekening van de maximaal toelaatbare faalkans.");
 
-            PropertyDescriptor bProperty = dynamicProperties[4];
+            PropertyDescriptor bProperty = dynamicProperties[5];
             PropertiesTestHelper.AssertRequiredPropertyDescriptorProperties(bProperty,
                                                                             lengthEffectCategory,
                                                                             "b [m]",
                                                                             "De parameter 'b' die gebruikt wordt voor het lengte-effect in berekening van de maximaal toelaatbare faalkans.",
                                                                             true);
 
-            PropertyDescriptor sectionLengthProperty = dynamicProperties[5];
+            PropertyDescriptor sectionLengthProperty = dynamicProperties[6];
             PropertiesTestHelper.AssertRequiredPropertyDescriptorProperties(sectionLengthProperty,
                                                                             lengthEffectCategory,
                                                                             "Lengte* [m]",
                                                                             "Totale lengte van het traject in meters (afgerond).",
                                                                             true);
 
-            PropertyDescriptor nProperty = dynamicProperties[6];
+            PropertyDescriptor nProperty = dynamicProperties[7];
             PropertiesTestHelper.AssertRequiredPropertyDescriptorProperties(nProperty,
                                                                             lengthEffectCategory,
                                                                             "N* [-]",
@@ -257,6 +265,7 @@
             Assert.IsTrue(properties.DynamicVisibleValidationMethod(nameof(properties.Code)));
             Assert.IsTrue(properties.DynamicVisibleValidationMethod(nameof(properties.IsRelevant)));
 
+            Assert.AreEqual(isRelevant, properties.DynamicVisibleValidationMethod(nameof(properties.Contribution)));
             Assert.AreEqual(isRelevant, properties.DynamicVisibleValidationMethod(nameof(properties.A)));
             Assert.AreEqual(isRelevant, properties.DynamicVisibleValidationMethod(nameof(properties.B)));
             Assert.AreEqual(isRelevant, properties.DynamicVisibleValidationMethod(nameof(properties.SectionLength)));