Index: Riskeer/Piping/src/Riskeer.Piping.Forms/Views/PipingScenariosView.cs
===================================================================
diff -u -r77d131dcd5b63b35ca48d9ffc6a2d8f40d2865bf -rbe102332fdeb4fe594150b7c99d859e9117e35fd
--- Riskeer/Piping/src/Riskeer.Piping.Forms/Views/PipingScenariosView.cs	(.../PipingScenariosView.cs)	(revision 77d131dcd5b63b35ca48d9ffc6a2d8f40d2865bf)
+++ Riskeer/Piping/src/Riskeer.Piping.Forms/Views/PipingScenariosView.cs	(.../PipingScenariosView.cs)	(revision be102332fdeb4fe594150b7c99d859e9117e35fd)
@@ -446,7 +446,7 @@
             if (e.KeyCode == Keys.Escape)
             {
                 ClearLengthEffectErrorMessage();
-                SetLengthEffectData(selectedFailureMechanismSection.ScenarioConfigurationPerSection.A);
+                SetLengthEffectData(selectedFailureMechanismSection.ScenarioConfigurationPerSection);
                 e.Handled = true;
             }
         }
@@ -504,7 +504,7 @@
 
             if (selectedFailureMechanismSection != null)
             {
-                SetLengthEffectData(selectedFailureMechanismSection.ScenarioConfigurationPerSection.A);
+                SetLengthEffectData(selectedFailureMechanismSection.ScenarioConfigurationPerSection);
             }
         }
 
@@ -519,11 +519,11 @@
             lengthEffectNRoundedTextBox.Text = string.Empty;
         }
 
-        private void SetLengthEffectData(double value)
+        private void SetLengthEffectData(PipingScenarioConfigurationPerFailureMechanismSection configuration)
         {
-            lengthEffectATextBox.Text = value.ToString(CultureInfo.CurrentCulture);
+            lengthEffectATextBox.Text = configuration.A.ToString(CultureInfo.CurrentCulture);
 
-            double n = failureMechanism.ProbabilityAssessmentInput.GetN(selectedFailureMechanismSection.Section.Length);
+            double n = configuration.GetN(failureMechanism.ProbabilityAssessmentInput.B);
             lengthEffectNRoundedTextBox.Text = new RoundedDouble(2, n).ToString();
         }
 
Index: Riskeer/Piping/test/Riskeer.Piping.Forms.Test/Views/PipingScenariosViewTest.cs
===================================================================
diff -u -r77d131dcd5b63b35ca48d9ffc6a2d8f40d2865bf -rbe102332fdeb4fe594150b7c99d859e9117e35fd
--- Riskeer/Piping/test/Riskeer.Piping.Forms.Test/Views/PipingScenariosViewTest.cs	(.../PipingScenariosViewTest.cs)	(revision 77d131dcd5b63b35ca48d9ffc6a2d8f40d2865bf)
+++ Riskeer/Piping/test/Riskeer.Piping.Forms.Test/Views/PipingScenariosViewTest.cs	(.../PipingScenariosViewTest.cs)	(revision be102332fdeb4fe594150b7c99d859e9117e35fd)
@@ -849,7 +849,7 @@
             Assert.IsFalse(radioButtonSemiProbabilistic.Checked);
             Assert.IsTrue(radioButtonProbabilistic.Checked);
             Assert.AreEqual("0,7", lengthEffectATextBox.Text);
-            Assert.AreEqual("1,01", lengthEffectNRoundedTextBox.Text);
+            Assert.AreEqual("1,22", lengthEffectNRoundedTextBox.Text);
 
             IPipingScenarioRow[] updatedRows = dataGridView.Rows.Cast<DataGridViewRow>()
                                                            .Select(r => r.DataBoundItem)
@@ -860,6 +860,109 @@
         }
 
         [Test]
+        public void GivenPipingScenariosView_WhenSettingNewAValue_ThenControlsUpdatedAndObserversNotified()
+        {
+            // Given
+            var mocks = new MockRepository();
+            var observer = mocks.StrictMock<IObserver>();
+            observer.Expect(o => o.UpdateObserver());
+            mocks.ReplayAll();
+
+            var surfaceLine = new PipingSurfaceLine("Surface line 1")
+            {
+                ReferenceLineIntersectionWorldPoint = new Point2D(0.0, 0.0)
+            };
+
+            surfaceLine.SetGeometry(new[]
+            {
+                new Point3D(0.0, 5.0, 0.0),
+                new Point3D(0.0, 0.0, 1.0),
+                new Point3D(0.0, -5.0, 0.0)
+            });
+
+            var failureMechanism = new PipingFailureMechanism();
+            failureMechanism.SetSections(new[]
+            {
+                FailureMechanismSectionTestFactory.CreateFailureMechanismSection(new[]
+                {
+                    new Point2D(0, 0),
+                    new Point2D(100, 0)
+                })
+            }, string.Empty);
+            failureMechanism.CalculationsGroup.Children.AddRange(new IPipingCalculationScenario<PipingInput>[]
+            {
+                new SemiProbabilisticPipingCalculationScenario
+                {
+                    Name = "Calculation 1",
+                    InputParameters =
+                    {
+                        SurfaceLine = surfaceLine,
+                        DampingFactorExit =
+                        {
+                            Mean = (RoundedDouble) 1.1111
+                        },
+                        PhreaticLevelExit =
+                        {
+                            Mean = (RoundedDouble) 2.2222
+                        },
+                        EntryPointL = (RoundedDouble) 3.3333,
+                        ExitPointL = (RoundedDouble) 4.4444
+                    },
+                    Contribution = (RoundedDouble) 0.13701
+                },
+                new SemiProbabilisticPipingCalculationScenario
+                {
+                    Name = "Calculation 2",
+                    InputParameters =
+                    {
+                        SurfaceLine = surfaceLine,
+                        DampingFactorExit =
+                        {
+                            Mean = (RoundedDouble) 5.5555
+                        },
+                        PhreaticLevelExit =
+                        {
+                            Mean = (RoundedDouble) 6.6666
+                        },
+                        EntryPointL = (RoundedDouble) 7.7777,
+                        ExitPointL = (RoundedDouble) 8.8888
+                    },
+                    IsRelevant = false
+                }
+            });
+
+            PipingScenarioConfigurationPerFailureMechanismSection affectedConfiguration =
+                failureMechanism.ScenarioConfigurationsPerFailureMechanismSection.First();
+            affectedConfiguration.Attach(observer);
+
+            ShowPipingScenariosView(failureMechanism);
+
+            var dataGridView = (DataGridView) new ControlTester("dataGridView").TheObject;
+            IPipingScenarioRow[] sectionResultRows = dataGridView.Rows.Cast<DataGridViewRow>()
+                                                                 .Select(r => r.DataBoundItem)
+                                                                 .Cast<IPipingScenarioRow>()
+                                                                 .ToArray();
+
+            // When
+            var textBoxTester = new TextBoxTester("lengthEffectATextBox");
+            textBoxTester.Enter("0,7");
+
+            // Then
+            Assert.AreEqual(0.7, affectedConfiguration.A);
+
+            var lengthEffectNRoundedTextBox = (TextBox) new ControlTester("lengthEffectNRoundedTextBox").TheObject;
+            Assert.AreEqual("1,23", lengthEffectNRoundedTextBox.Text);
+
+            IPipingScenarioRow[] updatedRows = dataGridView.Rows.Cast<DataGridViewRow>()
+                                                           .Select(r => r.DataBoundItem)
+                                                           .Cast<IPipingScenarioRow>()
+                                                           .ToArray();
+            CollectionAssert.AreNotEquivalent(sectionResultRows, updatedRows);
+
+            mocks.VerifyAll();
+        }
+
+        [Test]
         [SetCulture("nl-NL")]
         public void GivenPipingScenariosViewWithLengthEffectError_WhenSettingValidValue_ThenErrorClearedAndLengthEffectControlsUpdated()
         {
@@ -902,11 +1005,11 @@
             // Precondition
             var lengthEffectATextBox = (TextBox) new ControlTester("lengthEffectATextBox").TheObject;
             Assert.AreEqual("0,4", lengthEffectATextBox.Text);
-            
+
             ErrorProvider errorProvider = GetLengthEffectErrorProvider(view);
             string errorMessage = errorProvider.GetError(lengthEffectATextBox);
             Assert.IsEmpty(errorMessage);
-            
+
             var lengthEffectNRoundedTextBox = (TextBox) new ControlTester("lengthEffectNRoundedTextBox").TheObject;
             Assert.AreEqual("1,01", lengthEffectNRoundedTextBox.Text);
 
@@ -917,7 +1020,7 @@
             // Then
             errorMessage = errorProvider.GetError(lengthEffectATextBox);
             Assert.IsNotEmpty(errorMessage);
-            
+
             Assert.IsEmpty(lengthEffectNRoundedTextBox.Text);
         }
 
@@ -1812,7 +1915,7 @@
                 new FailureMechanismSection("Section 2", new[]
                 {
                     new Point2D(5.0, 0.0),
-                    new Point2D(10.0, 0.0)
+                    new Point2D(100.0, 0.0)
                 })
             });