Index: Ringtoets/Common/src/Ringtoets.Common.Data/UpdateDataStrategies/UpdateDataStrategyBase.cs
===================================================================
diff -u -r85b53922d59e2d43ef299322b89e0de7ea085c63 -r3e253f74f13c8f30551ec1135e6719b40074de89
--- Ringtoets/Common/src/Ringtoets.Common.Data/UpdateDataStrategies/UpdateDataStrategyBase.cs	(.../UpdateDataStrategyBase.cs)	(revision 85b53922d59e2d43ef299322b89e0de7ea085c63)
+++ Ringtoets/Common/src/Ringtoets.Common.Data/UpdateDataStrategies/UpdateDataStrategyBase.cs	(.../UpdateDataStrategyBase.cs)	(revision 3e253f74f13c8f30551ec1135e6719b40074de89)
@@ -130,7 +130,7 @@
         /// <exception cref="ArgumentException">Thrown when duplicate items are being added to the 
         /// <paramref name="targetDataCollection"/>.</exception>
         /// <exception cref="InvalidOperationException">Thrown when duplicate items are found during the 
-        /// update of the items to be updatd in the <paramref name="targetDataCollection"/>.</exception>
+        /// update of the items to be updated in the <paramref name="targetDataCollection"/>.</exception>
         private IEnumerable<IObservable> ModifyDataCollection(ObservableUniqueItemCollectionWithSourcePath<TTargetData> targetDataCollection,
                                                               IEnumerable<TTargetData> importedDataCollection,
                                                               string sourceFilePath)
@@ -141,7 +141,7 @@
             TTargetData[] objectsToBeUpdated = GetObjectsToBeUpdated(targetDataCollection, importedObjects).ToArray();
 
             var affectedObjects = new List<IObservable>();
-            if (objectsToBeAdded.Any() || objectsToBeRemoved.Any())
+            if (objectsToBeAdded.Any() || objectsToBeRemoved.Any() || objectsToBeUpdated.Any())
             {
                 affectedObjects.Add(targetDataCollection);
             }
Index: Ringtoets/Common/test/Ringtoets.Common.Data.Test/UpdateDataStrategies/UpdateDataStrategyBaseTest.cs
===================================================================
diff -u -r331995b9e0be4dcbb43e2a77e475282d66eb5530 -r3e253f74f13c8f30551ec1135e6719b40074de89
--- Ringtoets/Common/test/Ringtoets.Common.Data.Test/UpdateDataStrategies/UpdateDataStrategyBaseTest.cs	(.../UpdateDataStrategyBaseTest.cs)	(revision 331995b9e0be4dcbb43e2a77e475282d66eb5530)
+++ Ringtoets/Common/test/Ringtoets.Common.Data.Test/UpdateDataStrategies/UpdateDataStrategyBaseTest.cs	(.../UpdateDataStrategyBaseTest.cs)	(revision 3e253f74f13c8f30551ec1135e6719b40074de89)
@@ -276,7 +276,14 @@
             CollectionAssert.IsEmpty(strategy.RemoveDataCallArguments);
 
             CollectionAssert.AreEqual(currentCollection, collection);
-            CollectionAssert.AreEqual(currentCollection, affectedObjects);
+
+            IEnumerable<IObservable> expectedAffectedObjects = new IObservable[]
+            {
+                collection,
+                currentCollection[0],
+                currentCollection[1]
+            };
+            CollectionAssert.AreEqual(expectedAffectedObjects, affectedObjects);
         }
 
         [Test]
@@ -420,12 +427,12 @@
                                                                                    importedItems,
                                                                                    "path");
 
-            IEnumerable<IObservable> expectedAffectedObjects = new[]
+            IEnumerable<IObservable> expectedAffectedObjects = new IObservable[]
             {
+                collection,
                 itemOne,
                 itemTwo
             };
-
             CollectionAssert.AreEqual(expectedAffectedObjects, affectedObjects);
         }
 
Index: Ringtoets/Piping/test/Ringtoets.Piping.Plugin.Test/FileImporter/RingtoetsPipingSurfaceLineUpdateDataStrategyTest.cs
===================================================================
diff -u -rd16c525c53b03da07dd18853da6b8b256ede5b5a -r3e253f74f13c8f30551ec1135e6719b40074de89
--- Ringtoets/Piping/test/Ringtoets.Piping.Plugin.Test/FileImporter/RingtoetsPipingSurfaceLineUpdateDataStrategyTest.cs	(.../RingtoetsPipingSurfaceLineUpdateDataStrategyTest.cs)	(revision d16c525c53b03da07dd18853da6b8b256ede5b5a)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Plugin.Test/FileImporter/RingtoetsPipingSurfaceLineUpdateDataStrategyTest.cs	(.../RingtoetsPipingSurfaceLineUpdateDataStrategyTest.cs)	(revision 3e253f74f13c8f30551ec1135e6719b40074de89)
@@ -460,8 +460,9 @@
             Assert.AreSame(targetSurfaceLine, targetCollection[0]);
             Assert.AreEqual(readSurfaceLine, targetSurfaceLine);
 
-            CollectionAssert.AreEqual(new[]
+            CollectionAssert.AreEqual(new IObservable[]
             {
+                targetCollection,
                 targetSurfaceLine
             }, affectedObjects);
         }
@@ -702,6 +703,7 @@
 
             CollectionAssert.AreEquivalent(new IObservable[]
             {
+                collection,
                 affectedCalculation,
                 affectedInput,
                 affectedSurfaceLine
@@ -750,7 +752,8 @@
             };
 
             var failureMechanism = new PipingFailureMechanism();
-            failureMechanism.SurfaceLines.AddRange(new[]
+            RingtoetsPipingSurfaceLineCollection surfaceLineCollection = failureMechanism.SurfaceLines;
+            surfaceLineCollection.AddRange(new[]
             {
                 surfaceLine
             }, "path");
@@ -767,7 +770,7 @@
             var strategy = new RingtoetsPipingSurfaceLineUpdateDataStrategy(failureMechanism);
 
             // Call
-            IEnumerable<IObservable> affectedObjects = strategy.UpdateSurfaceLinesWithImportedData(failureMechanism.SurfaceLines,
+            IEnumerable<IObservable> affectedObjects = strategy.UpdateSurfaceLinesWithImportedData(surfaceLineCollection,
                                                                                                    new[]
                                                                                                    {
                                                                                                        importedSurfaceLine
@@ -777,6 +780,7 @@
             PipingInput calculationInput = calculation.InputParameters;
             CollectionAssert.AreEquivalent(new IObservable[]
             {
+                surfaceLineCollection,
                 surfaceLine,
                 calculationInput
             }, affectedObjects);
@@ -841,7 +845,8 @@
 
             var failureMechanism = new PipingFailureMechanism();
             failureMechanism.CalculationsGroup.Children.Add(calculation);
-            failureMechanism.SurfaceLines.AddRange(new[]
+            RingtoetsPipingSurfaceLineCollection surfaceLineCollection = failureMechanism.SurfaceLines;
+            surfaceLineCollection.AddRange(new[]
             {
                 surfaceLine
             }, "path");
@@ -857,7 +862,7 @@
             var strategy = new RingtoetsPipingSurfaceLineUpdateDataStrategy(failureMechanism);
 
             // Call
-            IEnumerable<IObservable> affectedObjects = strategy.UpdateSurfaceLinesWithImportedData(failureMechanism.SurfaceLines,
+            IEnumerable<IObservable> affectedObjects = strategy.UpdateSurfaceLinesWithImportedData(surfaceLineCollection,
                                                                                                    new[]
                                                                                                    {
                                                                                                        importedSurfaceLine
@@ -867,6 +872,7 @@
             PipingInput calculationInput = calculation.InputParameters;
             CollectionAssert.AreEquivalent(new IObservable[]
             {
+                surfaceLineCollection,
                 surfaceLine,
                 calculationInput
             }, affectedObjects);
@@ -929,7 +935,7 @@
 
             // Call
             IEnumerable<IObservable> affectedObjects = strategy.UpdateSurfaceLinesWithImportedData(failureMechanism.SurfaceLines,
-                                                                                                   Enumerable.Empty<RingtoetsPipingSurfaceLine>(), 
+                                                                                                   Enumerable.Empty<RingtoetsPipingSurfaceLine>(),
                                                                                                    "path").ToArray();
 
             // Assert
@@ -1013,7 +1019,8 @@
             failureMechanism.CalculationsGroup.Children.Add(affectedCalculation);
             failureMechanism.CalculationsGroup.Children.Add(unAffectedCalculation);
 
-            failureMechanism.SurfaceLines.AddRange(new[]
+            RingtoetsPipingSurfaceLineCollection surfaceLineCollection = failureMechanism.SurfaceLines;
+            surfaceLineCollection.AddRange(new[]
             {
                 affectedSurfaceLine
             }, "path");
@@ -1029,7 +1036,7 @@
             var strategy = new RingtoetsPipingSurfaceLineUpdateDataStrategy(failureMechanism);
 
             // Call
-            IEnumerable<IObservable> affectedObjects = strategy.UpdateSurfaceLinesWithImportedData(failureMechanism.SurfaceLines,
+            IEnumerable<IObservable> affectedObjects = strategy.UpdateSurfaceLinesWithImportedData(surfaceLineCollection,
                                                                                                    new[]
                                                                                                    {
                                                                                                        importedSurfaceLine
@@ -1039,6 +1046,7 @@
             PipingInput affectedInput = affectedCalculation.InputParameters;
             CollectionAssert.AreEquivalent(new IObservable[]
             {
+                surfaceLineCollection,
                 affectedInput,
                 affectedSurfaceLine
             }, affectedObjects);
@@ -1079,7 +1087,8 @@
             failureMechanism.CalculationsGroup.Children.Add(affectedCalculation);
             failureMechanism.CalculationsGroup.Children.Add(affectedCalculation);
 
-            failureMechanism.SurfaceLines.AddRange(new[]
+            RingtoetsPipingSurfaceLineCollection surfaceLineCollection = failureMechanism.SurfaceLines;
+            surfaceLineCollection.AddRange(new[]
             {
                 affectedSurfaceLine
             }, "path");
@@ -1089,7 +1098,7 @@
             var strategy = new RingtoetsPipingSurfaceLineUpdateDataStrategy(failureMechanism);
 
             // Call
-            IEnumerable<IObservable> affectedObjects = strategy.UpdateSurfaceLinesWithImportedData(failureMechanism.SurfaceLines,
+            IEnumerable<IObservable> affectedObjects = strategy.UpdateSurfaceLinesWithImportedData(surfaceLineCollection,
                                                                                                    new[]
                                                                                                    {
                                                                                                        importedSurfaceLine
@@ -1098,6 +1107,7 @@
             // Assert
             CollectionAssert.AreEquivalent(new IObservable[]
             {
+                surfaceLineCollection,
                 affectedSurfaceLine,
                 affectedCalculation.InputParameters
             }, affectedObjects);
@@ -1166,6 +1176,7 @@
 
             CollectionAssert.AreEquivalent(new IObservable[]
             {
+                collection,
                 affectedCalculation,
                 affectedInput,
                 affectedSurfaceLine
@@ -1237,6 +1248,7 @@
 
             CollectionAssert.AreEquivalent(new IObservable[]
             {
+                collection,
                 affectedCalculation,
                 affectedInput,
                 affectedSurfaceLine
Index: Ringtoets/Piping/test/Ringtoets.Piping.Plugin.Test/FileImporter/StochasticSoilModelUpdateDataStrategyTest.cs
===================================================================
diff -u -r81020313d965645986c0c89675374b16ae968f6b -r3e253f74f13c8f30551ec1135e6719b40074de89
--- Ringtoets/Piping/test/Ringtoets.Piping.Plugin.Test/FileImporter/StochasticSoilModelUpdateDataStrategyTest.cs	(.../StochasticSoilModelUpdateDataStrategyTest.cs)	(revision 81020313d965645986c0c89675374b16ae968f6b)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Plugin.Test/FileImporter/StochasticSoilModelUpdateDataStrategyTest.cs	(.../StochasticSoilModelUpdateDataStrategyTest.cs)	(revision 3e253f74f13c8f30551ec1135e6719b40074de89)
@@ -279,8 +279,9 @@
             // Assert
             Assert.AreEqual(1, targetCollection.Count);
             Assert.AreSame(existingModel, targetCollection[0]);
-            CollectionAssert.AreEquivalent(new[]
+            CollectionAssert.AreEquivalent(new IObservable[]
             {
+                targetCollection,
                 existingModel
             }, affectedObjects);
         }
@@ -313,6 +314,7 @@
             Assert.AreEqual(2, targetCollection[0].StochasticSoilProfiles.Count);
             CollectionAssert.AreEquivalent(new IObservable[]
             {
+                targetCollection,
                 existingModel
             }, affectedObjects);
         }
@@ -425,6 +427,7 @@
 
             CollectionAssert.AreEquivalent(new IObservable[]
             {
+                targetCollection,
                 firstSoilModel,
                 calculationWithUpdatedProfile,
                 calculationWithUpdatedProfile.InputParameters,