Index: Ringtoets/Piping/src/Ringtoets.Piping.Forms/Views/PipingFailureMechanismView.cs
===================================================================
diff -u -r41a0ca88d60c400e5737e952da8c3ca57dea83e7 -rdb376befd1575a80aa5f4d3e84f803e132ac1a75
--- Ringtoets/Piping/src/Ringtoets.Piping.Forms/Views/PipingFailureMechanismView.cs	(.../PipingFailureMechanismView.cs)	(revision 41a0ca88d60c400e5737e952da8c3ca57dea83e7)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Forms/Views/PipingFailureMechanismView.cs	(.../PipingFailureMechanismView.cs)	(revision db376befd1575a80aa5f4d3e84f803e132ac1a75)
@@ -22,6 +22,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Windows.Forms;
+using Core.Common.Base;
 using Core.Common.Base.Geometry;
 using Core.Components.DotSpatial.Forms;
 using Core.Components.Gis;
@@ -31,7 +32,7 @@
 
 namespace Ringtoets.Piping.Forms.Views
 {
-    public partial class PipingFailureMechanismView :  UserControl, IMapView
+    public partial class PipingFailureMechanismView :  UserControl, IMapView, IObserver
     {
         private readonly BaseMap map;
         private PipingFailureMechanismContext data;
@@ -60,7 +61,9 @@
 
                 if (data != null)
                 {
+                    data.Parent.Detach(this);
                     SetDataToMap();
+                    data.Parent.Attach(this);
                 }
             }
         }
@@ -111,5 +114,13 @@
         {
             return data.Parent.HydraulicBoundaryDatabase != null && data.Parent.HydraulicBoundaryDatabase.Locations.Any();
         }
+
+        public void UpdateObserver()
+        {
+            if (data != null)
+            {
+                SetDataToMap();
+            }
+        }
     }
 }
\ No newline at end of file
Index: Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/Views/PipingFailureMechanismViewTest.cs
===================================================================
diff -u -r41a0ca88d60c400e5737e952da8c3ca57dea83e7 -rdb376befd1575a80aa5f4d3e84f803e132ac1a75
--- Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/Views/PipingFailureMechanismViewTest.cs	(.../PipingFailureMechanismViewTest.cs)	(revision 41a0ca88d60c400e5737e952da8c3ca57dea83e7)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/Views/PipingFailureMechanismViewTest.cs	(.../PipingFailureMechanismViewTest.cs)	(revision db376befd1575a80aa5f4d3e84f803e132ac1a75)
@@ -1,10 +1,13 @@
 using System.Collections.Generic;
+using System.Linq;
 using System.Windows.Forms;
+using Core.Common.Base;
 using Core.Common.Base.Geometry;
 using Core.Common.Controls.Views;
 using Core.Components.DotSpatial.Forms;
 using Core.Components.Gis.Data;
 using NUnit.Framework;
+using Rhino.Mocks;
 using Ringtoets.Common.Data;
 using Ringtoets.HydraRing.Data;
 using Ringtoets.Piping.Data;
@@ -25,95 +28,199 @@
             // Assert
             Assert.IsInstanceOf<UserControl>(view);
             Assert.IsInstanceOf<IView>(view);
+            Assert.IsInstanceOf<IObserver>(view);
+            Assert.NotNull(view.Map);
+            Assert.IsNull(view.Data);
         }
 
         [Test]
-        public void DefaultConstructor_Always_AddsBaseMap()
+        public void DefaultConstructor_Always_AddsBaseMapWithoutData()
         {
             // Call
             var view = new PipingFailureMechanismView();
 
             // Assert
             Assert.AreEqual(1, view.Controls.Count);
-            object mapObject = view.Controls[0];
-            Assert.IsInstanceOf<BaseMap>(mapObject);
-
-            var map = (BaseMap)mapObject;
-            Assert.AreEqual(DockStyle.Fill, map.Dock);
-            Assert.NotNull(view.Map);
+            var mapObject = view.Controls[0] as BaseMap;
+            Assert.NotNull(mapObject);
+            Assert.AreEqual(DockStyle.Fill, mapObject.Dock);
+            Assert.IsNull(mapObject.Data);
         }
 
         [Test]
-        public void Data_ReferenceLineNull_NoLineDataSet()
+        public void Data_EmptyAssessmentSection_NoMapDataSet()
         {
             // Setup
             var view = new PipingFailureMechanismView();
             var map = (BaseMap)view.Controls[0];
 
+            var assessmentSectionBase = new AssessmentSectionBaseTestClass();
+
+            var pipingFailureMechanism = new PipingFailureMechanism();
+
+            var pipingContext = new PipingFailureMechanismContext(pipingFailureMechanism, assessmentSectionBase);
+
+            // Call
+            view.Data = pipingContext;
+
+            // Assert
+            var mapData = (MapDataCollection)map.Data;
+
+            Assert.AreEqual(0, mapData.List.Count);
+        }
+
+        [Test]
+        public void Data_SetToMapPointData_MapDataSet()
+        {
+            // Setup
+            var view = new PipingFailureMechanismView();
+            var map = (BaseMap)view.Controls[0];
             var assessmentSectionBase = new AssessmentSectionBaseTestClass
             {
                 HydraulicBoundaryDatabase = new HydraulicBoundaryDatabase()
             };
             assessmentSectionBase.HydraulicBoundaryDatabase.Locations.Add(new HydraulicBoundaryLocation(1, "test", 1.0, 2.0));
 
             var pipingFailureMechanism = new PipingFailureMechanism();
-
             var pipingContext = new PipingFailureMechanismContext(pipingFailureMechanism, assessmentSectionBase);
 
             // Call
             view.Data = pipingContext;
 
             // Assert
-            var mapData = (MapDataCollection)map.Data;
-
-            Assert.AreEqual(1, mapData.List.Count);
-            Assert.IsNotInstanceOf<MapLineData>(mapData.List[0]);
+            Assert.AreSame(pipingContext, view.Data);
+            Assert.IsInstanceOf<MapDataCollection>(map.Data);
+            var mapData = map.Data as MapDataCollection;
+            Assert.IsNotNull(mapData);
+            Assert.IsTrue(mapData.List.Any(md => md is MapPointData));
         }
 
         [Test]
-        public void Data_HydraulicBoundaryDatabaseNull_NoPointDataSet()
+        public void UpdateObserver_HydraulicBoundaryDatabaseUpdated_SetNewMapDataData()
         {
             // Setup
             var view = new PipingFailureMechanismView();
             var map = (BaseMap)view.Controls[0];
 
+            var mocks = new MockRepository();
+            var observer = mocks.StrictMock<IObserver>();
+            observer.Expect(o => o.UpdateObserver());
+
+            mocks.ReplayAll();
+
             var assessmentSectionBase = new AssessmentSectionBaseTestClass
             {
-                ReferenceLine = new ReferenceLine()
+                HydraulicBoundaryDatabase = new HydraulicBoundaryDatabase()
             };
-            assessmentSectionBase.ReferenceLine.SetGeometry(new List<Point2D>
-            {
-                new Point2D(1.0, 2.0),
-                new Point2D(2.0, 1.0)
-            });
+            assessmentSectionBase.HydraulicBoundaryDatabase.Locations.Add(new HydraulicBoundaryLocation(1, "test", 1.0, 2.0));
+            assessmentSectionBase.Attach(observer);
 
             var pipingFailureMechanism = new PipingFailureMechanism();
-
             var pipingContext = new PipingFailureMechanismContext(pipingFailureMechanism, assessmentSectionBase);
 
-            // Call
             view.Data = pipingContext;
+            var mapData = map.Data;
 
+            assessmentSectionBase.HydraulicBoundaryDatabase = new HydraulicBoundaryDatabase();
+            assessmentSectionBase.HydraulicBoundaryDatabase.Locations.Add(new HydraulicBoundaryLocation(2, "test2", 2.0, 3.0));
+
+            // Call
+            assessmentSectionBase.NotifyObservers();
+
             // Assert
-            var mapData = (MapDataCollection)map.Data;
+            Assert.AreNotEqual(mapData, map.Data);
+            Assert.IsInstanceOf<MapDataCollection>(map.Data);
+            mocks.VerifyAll();
+        }
 
-            Assert.AreEqual(1, mapData.List.Count);
-            Assert.IsNotInstanceOf<MapPointData>(mapData.List[0]);
+        [Test]
+        public void UpdateObserver_OtherAssessmentSectionUpdated_MapDataNotUpdated()
+        {
+            // Setup
+            var view = new PipingFailureMechanismView();
+            var map = (BaseMap)view.Controls[0];
+
+            var mocks = new MockRepository();
+            var observer = mocks.StrictMock<IObserver>();
+            observer.Expect(o => o.UpdateObserver());
+
+            mocks.ReplayAll();
+
+            var assessmentSectionBase = new AssessmentSectionBaseTestClass
+            {
+                HydraulicBoundaryDatabase = new HydraulicBoundaryDatabase()
+            };
+            assessmentSectionBase.HydraulicBoundaryDatabase.Locations.Add(new HydraulicBoundaryLocation(1, "test", 1.0, 2.0));
+            assessmentSectionBase.Attach(observer);
+
+            var pipingFailureMechanism = new PipingFailureMechanism();
+            var pipingContext = new PipingFailureMechanismContext(pipingFailureMechanism, assessmentSectionBase);
+
+            view.Data = pipingContext;
+
+            var assessmentSectionBase2 = new AssessmentSectionBaseTestClass
+            {
+                HydraulicBoundaryDatabase = new HydraulicBoundaryDatabase()
+            };
+            assessmentSectionBase2.HydraulicBoundaryDatabase.Locations.Add(new HydraulicBoundaryLocation(2, "test2", 2.0, 3.0));
+            assessmentSectionBase2.Attach(observer);
+
+            // Call
+            assessmentSectionBase2.NotifyObservers();
+
+            // Assert
+            Assert.AreEqual(pipingContext, view.Data);
+            Assert.IsInstanceOf<MapDataCollection>(map.Data);
+            mocks.VerifyAll();
         }
 
         [Test]
-        public void Data_SetToNull_BaseMapNoFeatures()
+        public void UpdateObserver_DataNull_MapDataNotUpdated()
         {
             // Setup
             var view = new PipingFailureMechanismView();
             var map = (BaseMap)view.Controls[0];
 
+            var mocks = new MockRepository();
+            var observer = mocks.StrictMock<IObserver>();
+            observer.Expect(o => o.UpdateObserver());
+
+            mocks.ReplayAll();
+
+            var assessmentSectionBase = new AssessmentSectionBaseTestClass
+            {
+                ReferenceLine = new ReferenceLine()
+            };
+            assessmentSectionBase.ReferenceLine.SetGeometry(new List<Point2D>
+            {
+                new Point2D(1.0, 2.0),
+                new Point2D(2.0, 1.0)
+            });
+
+            var pipingFailureMechanism = new PipingFailureMechanism();
+            var pipingContext = new PipingFailureMechanismContext(pipingFailureMechanism, assessmentSectionBase);
+
+            view.Data = pipingContext;
+
+            assessmentSectionBase.Attach(observer);
+
+            MapData dataBeforeUpdate = map.Data;
+            view.Data = null;
+
+            assessmentSectionBase.ReferenceLine = new ReferenceLine();
+            assessmentSectionBase.ReferenceLine.SetGeometry(new List<Point2D>
+            {
+                new Point2D(2.0, 5.0),
+                new Point2D(34.0, 2.0)
+            });
+
             // Call
-            TestDelegate testDelegate = () => view.Data = null;
+            assessmentSectionBase.NotifyObservers();
 
             // Assert
-            Assert.DoesNotThrow(testDelegate);
-            Assert.IsNull(map.Data);
+            Assert.IsNull(view.Data);
+            Assert.AreEqual(dataBeforeUpdate, map.Data);
+            mocks.VerifyAll();
         }
 
         private class AssessmentSectionBaseTestClass : AssessmentSectionBase