Index: Ringtoets/Common/src/Ringtoets.Common.Forms/Views/FailureMechanismSectionsProbabilityAssessmentView.cs
===================================================================
diff -u -rfdfadac14aca46b2ffde145e6532ee7bb18d2507 -r303f338bc9e42d1d7621666fdf83b93a11f28b64
--- Ringtoets/Common/src/Ringtoets.Common.Forms/Views/FailureMechanismSectionsProbabilityAssessmentView.cs	(.../FailureMechanismSectionsProbabilityAssessmentView.cs)	(revision fdfadac14aca46b2ffde145e6532ee7bb18d2507)
+++ Ringtoets/Common/src/Ringtoets.Common.Forms/Views/FailureMechanismSectionsProbabilityAssessmentView.cs	(.../FailureMechanismSectionsProbabilityAssessmentView.cs)	(revision 303f338bc9e42d1d7621666fdf83b93a11f28b64)
@@ -37,6 +37,7 @@
         private readonly ProbabilityAssessmentInput probabilityAssessmentInput;
 
         private readonly Observer failureMechanismObserver;
+        private double currentA;
 
         /// <summary>
         /// Creates a new instance of <see cref="FailureMechanismSectionsProbabilityAssessmentView"/>.
@@ -70,6 +71,8 @@
 
         protected override void SetDataGridViewControlData()
         {
+            currentA = probabilityAssessmentInput.A;
+
             failureMechanismSectionsDataGridViewControl.SetDataSource(
                 sections.Select(section => new FailureMechanismSectionProbabilityAssessmentRow(section, probabilityAssessmentInput))
                         .ToArray());
@@ -84,6 +87,13 @@
 
         private void HandleProbabilityAssessmentInputChange()
         {
+            if (currentA.Equals(probabilityAssessmentInput.A))
+            {
+                return;
+            }
+
+            currentA = probabilityAssessmentInput.A;
+
             failureMechanismSectionsDataGridViewControl.RefreshDataGridView();
         }
     }
Index: Ringtoets/Common/test/Ringtoets.Common.Forms.Test/Views/FailureMechanismSectionProbabilityAssessmentRowTest.cs
===================================================================
diff -u -r0a15d24f5c981c82d77f10cd67ab9171c4ee555a -r303f338bc9e42d1d7621666fdf83b93a11f28b64
--- Ringtoets/Common/test/Ringtoets.Common.Forms.Test/Views/FailureMechanismSectionProbabilityAssessmentRowTest.cs	(.../FailureMechanismSectionProbabilityAssessmentRowTest.cs)	(revision 0a15d24f5c981c82d77f10cd67ab9171c4ee555a)
+++ Ringtoets/Common/test/Ringtoets.Common.Forms.Test/Views/FailureMechanismSectionProbabilityAssessmentRowTest.cs	(.../FailureMechanismSectionProbabilityAssessmentRowTest.cs)	(revision 303f338bc9e42d1d7621666fdf83b93a11f28b64)
@@ -68,7 +68,7 @@
         }
 
         [Test]
-        public void GivenRow_WhenProbabilityAssessmentInputChanged_ThenNChangedAccordingly()
+        public void GivenRow_WhenProbabilityAssessmentInputChanged_ThenLengthEffectChangedAccordingly()
         {
             // Given
             var random = new Random(39);
Index: Ringtoets/Common/test/Ringtoets.Common.Forms.Test/Views/FailureMechanismSectionsProbabilityAssessmentViewTest.cs
===================================================================
diff -u -r828558d9bcb3134b16a9acee46e4cba9d94ae893 -r303f338bc9e42d1d7621666fdf83b93a11f28b64
--- Ringtoets/Common/test/Ringtoets.Common.Forms.Test/Views/FailureMechanismSectionsProbabilityAssessmentViewTest.cs	(.../FailureMechanismSectionsProbabilityAssessmentViewTest.cs)	(revision 828558d9bcb3134b16a9acee46e4cba9d94ae893)
+++ Ringtoets/Common/test/Ringtoets.Common.Forms.Test/Views/FailureMechanismSectionsProbabilityAssessmentViewTest.cs	(.../FailureMechanismSectionsProbabilityAssessmentViewTest.cs)	(revision 303f338bc9e42d1d7621666fdf83b93a11f28b64)
@@ -202,7 +202,7 @@
         }
 
         [Test]
-        public void GivenViewWithSections_WhenFailureMechanismNotifiesChangeAndProbabilityAssessmentInputChanged_ThenDataGridViewUpdated()
+        public void GivenViewWithSections_WhenFailureMechanismNotifiesChangeAndProbabilityAssessmentInputChanged_ThenDataGridViewRefreshed()
         {
             // Given
             var failureMechanism = new TestFailureMechanism();
@@ -214,6 +214,12 @@
                                                                                                                                   failureMechanism,
                                                                                                                                   probabilityAssessmentInput))
             {
+                DataGridView sectionsDataGridView = GetSectionsDataGridView(view);
+
+                var count = 0;
+
+                sectionsDataGridView.DataSourceChanged += (s, e) => { count++; };
+
                 DataGridViewControl sectionsDataGridViewControl = GetSectionsDataGridViewControl(view);
 
                 // Precondition
@@ -224,10 +230,39 @@
                 failureMechanism.NotifyObservers();
 
                 // Then
+                Assert.AreEqual(0, count);
                 AssertSectionsDataGridViewControl(failureMechanism.Sections.ToArray(), probabilityAssessmentInput, sectionsDataGridViewControl);
             }
         }
 
+        [Test]
+        public void GivenViewWithSections_WhenFailureMechanismNotifiesChangeButNothingRelevantChanged_ThenDataGridViewNotUpdated()
+        {
+            // Given
+            var failureMechanism = new TestFailureMechanism();
+            failureMechanism.AddSection(CreateFailureMechanismSection("a", 0.0, 0.0, 1.0, 1.0));
+
+            ProbabilityAssessmentInput probabilityAssessmentInput = CreateProbabilityAssessmentInput();
+
+            using (FailureMechanismSectionsProbabilityAssessmentView view = ShowFailureMechanismSectionsProbabilityAssessmentView(failureMechanism.Sections,
+                                                                                                                                  failureMechanism,
+                                                                                                                                  probabilityAssessmentInput))
+            {
+                DataGridView sectionsDataGridView = GetSectionsDataGridView(view);
+
+                var count = 0;
+
+                sectionsDataGridView.Invalidated += (s, e) => { count++; };
+
+                // When
+                failureMechanism.Contribution = 50;
+                failureMechanism.NotifyObservers();
+
+                // Then
+                Assert.AreEqual(0, count);
+            }
+        }
+
         private static FailureMechanismSection CreateFailureMechanismSection(string name, double x1, double y1, double x2, double y2)
         {
             return new FailureMechanismSection(name, new[]
@@ -249,6 +284,11 @@
             return ControlTestHelper.GetControls<DataGridViewControl>(view, "failureMechanismSectionsDataGridViewControl").Single();
         }
 
+        private static DataGridView GetSectionsDataGridView(FailureMechanismSectionsView view)
+        {
+            return ControlTestHelper.GetControls<DataGridView>(view, "dataGridView").Single();
+        }
+
         private static void AssertSectionsDataGridViewControl(FailureMechanismSection[] sections,
                                                               ProbabilityAssessmentInput probabilityAssessmentInput,
                                                               DataGridViewControl sectionsDataGridViewControl)