Index: Core/Common/src/Core.Common.Base/Core.Common.Base.csproj
===================================================================
diff -u -r1b4f4720632f9a691837fa97e777a4637b6739c8 -r0dbf681489bfe1d279eef99030f9ee13abebbb23
--- Core/Common/src/Core.Common.Base/Core.Common.Base.csproj	(.../Core.Common.Base.csproj)	(revision 1b4f4720632f9a691837fa97e777a4637b6739c8)
+++ Core/Common/src/Core.Common.Base/Core.Common.Base.csproj	(.../Core.Common.Base.csproj)	(revision 0dbf681489bfe1d279eef99030f9ee13abebbb23)
@@ -97,6 +97,7 @@
     <Compile Include="Geometry\Segment2DIntersectSegment2DResult.cs" />
     <Compile Include="IO\FileImporterBase.cs" />
     <Compile Include="IO\ProgressChangedDelegate.cs" />
+    <Compile Include="Observer.cs" />
     <Compile Include="Storage\StorageException.cs" />
     <Compile Include="Storage\StorageValidationException.cs" />
     <Compile Include="Storage\CouldNotConnectException.cs" />
Index: Core/Common/src/Core.Common.Base/Observer.cs
===================================================================
diff -u
--- Core/Common/src/Core.Common.Base/Observer.cs	(revision 0)
+++ Core/Common/src/Core.Common.Base/Observer.cs	(revision 0dbf681489bfe1d279eef99030f9ee13abebbb23)
@@ -0,0 +1,84 @@
+// Copyright (C) Stichting Deltares 2016. All rights reserved.
+//
+// This file is part of Ringtoets.
+//
+// Ringtoets is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+//
+// All names, logos, and references to "Deltares" are registered trademarks of
+// Stichting Deltares and remain full property of Stichting Deltares at all times.
+// All rights reserved.
+
+using System;
+
+namespace Core.Common.Base
+{
+    /// <summary>
+    /// Class that implements the <see cref="IObserver"/> pattern.
+    /// </summary>
+    /// <remarks>
+    /// The <see cref="Observable"/> being observed by instances of this class can be dynamically changed.
+    /// </remarks>
+    public class Observer : IObserver, IDisposable
+    {
+        private readonly Action updateObserverAction;
+        private IObservable observable;
+
+        /// <summary>
+        /// Creates a new instance of the <see cref="Observer"/> class.
+        /// </summary>
+        /// <param name="updateObserverAction">The <see cref="UpdateObserver"/> action to perform on notifications coming from <see cref="Observable"/>.</param>
+        public Observer(Action updateObserverAction)
+        {
+            this.updateObserverAction = updateObserverAction;
+        }
+
+        /// <summary>
+        /// Gets or sets the object to observe.
+        /// </summary>
+        public IObservable Observable
+        {
+            get
+            {
+                return observable;
+            }
+            set
+            {
+                if (observable != null)
+                {
+                    observable.Detach(this);
+                }
+
+                observable = value;
+
+                if (observable != null)
+                {
+                    observable.Attach(this);
+                }
+            }
+        }
+
+        public void UpdateObserver()
+        {
+            updateObserverAction();
+        }
+
+        public void Dispose()
+        {
+            if (observable != null)
+            {
+                observable.Detach(this);
+            }
+        }
+    }
+}
\ No newline at end of file
Index: Core/Common/test/Core.Common.Base.Test/Core.Common.Base.Test.csproj
===================================================================
diff -u -r1b4f4720632f9a691837fa97e777a4637b6739c8 -r0dbf681489bfe1d279eef99030f9ee13abebbb23
--- Core/Common/test/Core.Common.Base.Test/Core.Common.Base.Test.csproj	(.../Core.Common.Base.Test.csproj)	(revision 1b4f4720632f9a691837fa97e777a4637b6739c8)
+++ Core/Common/test/Core.Common.Base.Test/Core.Common.Base.Test.csproj	(.../Core.Common.Base.Test.csproj)	(revision 0dbf681489bfe1d279eef99030f9ee13abebbb23)
@@ -91,6 +91,7 @@
     <Compile Include="Data\ProjectComparerTest.cs" />
     <Compile Include="IO\FileImporterBaseTest.cs" />
     <Compile Include="ObservableTest.cs" />
+    <Compile Include="ObserverTest.cs" />
     <Compile Include="Plugin\ApplicationCoreTest.cs" />
     <Compile Include="Service\ActivityTest.cs" />
     <Compile Include="Plugin\ApplicationPluginTest.cs" />
Index: Core/Common/test/Core.Common.Base.Test/ObserverTest.cs
===================================================================
diff -u
--- Core/Common/test/Core.Common.Base.Test/ObserverTest.cs	(revision 0)
+++ Core/Common/test/Core.Common.Base.Test/ObserverTest.cs	(revision 0dbf681489bfe1d279eef99030f9ee13abebbb23)
@@ -0,0 +1,103 @@
+// Copyright (C) Stichting Deltares 2016. All rights reserved.
+//
+// This file is part of Ringtoets.
+//
+// Ringtoets is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+//
+// All names, logos, and references to "Deltares" are registered trademarks of
+// Stichting Deltares and remain full property of Stichting Deltares at all times.
+// All rights reserved.
+
+using NUnit.Framework;
+
+namespace Core.Common.Base.Test
+{
+    [TestFixture]
+    public class ObserverTest
+    {
+        [Test]
+        public void DefaultConstructor_DefaultValues()
+        {
+            // Call
+            var observer = new Observer(() => { });
+
+            // Assert
+            Assert.IsInstanceOf<IObserver>(observer);
+            Assert.IsNull(observer.Observable);
+        }
+
+        [Test]
+        public void Observer_WithObservable_NotifyObserversResultsInPerformingUpdateObserversAction()
+        {
+            // Setup
+            var counter = 0;
+            var observable = new TestObservable();
+            var observer = new Observer(() => counter++)
+            {
+                Observable = observable
+            };
+
+            // Call
+            observable.NotifyObservers();
+
+            // Assert
+            Assert.AreEqual(1, counter);
+        }
+
+        [Test]
+        public void Observer_WithObservableSetAndThenUnset_NotifyObserversNoLongerResultsInPerformingUpdateObserversAction()
+        {
+            // Setup
+            var counter = 0;
+            var observable = new TestObservable();
+            var observer = new Observer(() => counter++)
+            {
+                Observable = observable
+            };
+
+            observer.Observable = null;
+
+            // Call
+            observable.NotifyObservers();
+
+            // Assert
+            Assert.AreEqual(0, counter);
+        }
+
+        [Test]
+        public void Observer_WithObservableSetAndThenDisposed_NotifyObserversNoLongerResultsInPerformingUpdateObserversAction()
+        {
+            // Setup
+            var counter = 0;
+            var observable = new TestObservable();
+            var observer = new Observer(() => counter++)
+            {
+                Observable = observable
+            };
+
+            observer.Dispose();
+
+            // Call
+            observable.NotifyObservers();
+
+            // Assert
+            Assert.AreEqual(0, counter);
+        }
+
+        private class TestObservable : Observable
+        {
+
+        }
+    }
+}
Index: Ringtoets/Piping/src/Ringtoets.Piping.Forms/Views/PipingCalculationsView.cs
===================================================================
diff -u -r13919719112d513d5782320d8c0829c69b5e8d9e -r0dbf681489bfe1d279eef99030f9ee13abebbb23
--- Ringtoets/Piping/src/Ringtoets.Piping.Forms/Views/PipingCalculationsView.cs	(.../PipingCalculationsView.cs)	(revision 13919719112d513d5782320d8c0829c69b5e8d9e)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Forms/Views/PipingCalculationsView.cs	(.../PipingCalculationsView.cs)	(revision 0dbf681489bfe1d279eef99030f9ee13abebbb23)
@@ -300,44 +300,6 @@
             }
         }
 
-        private class Observer : IObserver
-        {
-            private readonly Action updateObserverAction;
-            private IObservable observable;
-
-            public Observer(Action updateObserverAction)
-            {
-                this.updateObserverAction = updateObserverAction;
-            }
-
-            public IObservable Observable
-            {
-                get
-                {
-                    return observable;
-                }
-                set
-                {
-                    if (observable != null)
-                    {
-                        observable.Detach(this);
-                    }
-
-                    observable = value;
-
-                    if (observable != null)
-                    {
-                        observable.Attach(this);
-                    }
-                }
-            }
-
-            public void UpdateObserver()
-            {
-                updateObserverAction();
-            }
-        }
-
         private class PipingCalculationRow
         {
             private readonly PipingCalculation pipingCalculation;