Index: Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Plugin/MacroStabilityInwardsPlugin.cs
===================================================================
diff -u -r6bc9f77c55e1fba2e86203b22778f8a405aee2eb -r7839a8e4dc28510da33a0dd64e021ccc76c392bb
--- Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Plugin/MacroStabilityInwardsPlugin.cs	(.../MacroStabilityInwardsPlugin.cs)	(revision 6bc9f77c55e1fba2e86203b22778f8a405aee2eb)
+++ Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Plugin/MacroStabilityInwardsPlugin.cs	(.../MacroStabilityInwardsPlugin.cs)	(revision 7839a8e4dc28510da33a0dd64e021ccc76c392bb)
@@ -250,7 +250,7 @@
                 GetViewName = (view, context) => RingtoetsCommonFormsResources.Calculation_Input,
                 Image = RingtoetsCommonFormsResources.GenericInputOutputIcon,
                 CloseForData = CloseInputViewForData,
-                CreateInstance = context => new MacroStabilityInwardsInputView(context.MacroStabilityInwardsCalculation, 
+                CreateInstance = context => new MacroStabilityInwardsInputView(context.MacroStabilityInwardsCalculation,
                                                                                context.AssessmentSection,
                                                                                () => context.AssessmentSection.GetNormativeHydraulicBoundaryLocationCalculation(context.WrappedData.HydraulicBoundaryLocation))
             };
@@ -557,17 +557,18 @@
 
         #endregion
 
-        private void CalculateAll(MacroStabilityInwardsFailureMechanismContext failureMechanismContext)
+        private void CalculateAll(MacroStabilityInwardsFailureMechanismContext context)
         {
-            IEnumerable<MacroStabilityInwardsCalculation> calculations = GetAllMacroStabilityInwardsCalculations(failureMechanismContext.WrappedData);
-
-            CalculateAll(calculations, failureMechanismContext.Parent);
+            ActivityProgressDialogRunner.Run(
+                Gui.MainWindow,
+                MacroStabilityInwardsCalculationActivityFactory.CreateCalculationActivities(context.WrappedData, context.Parent));
         }
 
         private void CalculateAll(CalculationGroup group, MacroStabilityInwardsCalculationGroupContext context)
         {
-            MacroStabilityInwardsCalculation[] calculations = group.GetCalculations().OfType<MacroStabilityInwardsCalculation>().ToArray();
-            CalculateAll(calculations, context.AssessmentSection);
+            ActivityProgressDialogRunner.Run(
+                Gui.MainWindow,
+                MacroStabilityInwardsCalculationActivityFactory.CreateCalculationActivities(group, context.AssessmentSection));
         }
 
         private static void ValidateAll(IEnumerable<MacroStabilityInwardsCalculation> calculations, IAssessmentSection assessmentSection)
@@ -578,16 +579,6 @@
             }
         }
 
-        private void CalculateAll(IEnumerable<MacroStabilityInwardsCalculation> calculations, IAssessmentSection assessmentSection)
-        {
-            ActivityProgressDialogRunner.Run(
-                Gui.MainWindow,
-                calculations
-                    .Select(pc => new MacroStabilityInwardsCalculationActivity(pc,
-                                                                               GetNormativeAssessmentLevel(assessmentSection, pc)))
-                    .ToList());
-        }
-
         #region MacroStabilityInwardsSurfaceLinesContext TreeNodeInfo
 
         private ContextMenuStrip MacroStabilityInwardsSurfaceLinesContextContextMenuStrip(MacroStabilityInwardsSurfaceLinesContext nodeData, object parentData, TreeViewControl treeViewControl)
@@ -673,11 +664,6 @@
                           .Build();
         }
 
-        private static IEnumerable<MacroStabilityInwardsCalculation> GetAllMacroStabilityInwardsCalculations(MacroStabilityInwardsFailureMechanism failureMechanism)
-        {
-            return failureMechanism.Calculations.OfType<MacroStabilityInwardsCalculation>();
-        }
-
         private static object[] FailureMechanismEnabledChildNodeObjects(MacroStabilityInwardsFailureMechanismContext macroStabilityInwardsFailureMechanismContext)
         {
             MacroStabilityInwardsFailureMechanism wrappedData = macroStabilityInwardsFailureMechanismContext.WrappedData;
@@ -797,8 +783,9 @@
 
         private void PerformCalculation(MacroStabilityInwardsCalculation calculation, MacroStabilityInwardsCalculationScenarioContext context)
         {
-            ActivityProgressDialogRunner.Run(Gui.MainWindow,
-                                             new MacroStabilityInwardsCalculationActivity(calculation, GetNormativeAssessmentLevel(context.AssessmentSection, calculation)));
+            ActivityProgressDialogRunner.Run(
+                Gui.MainWindow,
+                MacroStabilityInwardsCalculationActivityFactory.CreateCalculationActivity(calculation, context.AssessmentSection));
         }
 
         #endregion
Index: Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Service/MacroStabilityInwardsCalculationActivity.cs
===================================================================
diff -u -r83bf97213a11e77a77f1bd6b35eef856922ff4d7 -r7839a8e4dc28510da33a0dd64e021ccc76c392bb
--- Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Service/MacroStabilityInwardsCalculationActivity.cs	(.../MacroStabilityInwardsCalculationActivity.cs)	(revision 83bf97213a11e77a77f1bd6b35eef856922ff4d7)
+++ Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Service/MacroStabilityInwardsCalculationActivity.cs	(.../MacroStabilityInwardsCalculationActivity.cs)	(revision 7839a8e4dc28510da33a0dd64e021ccc76c392bb)
@@ -30,7 +30,7 @@
     /// <summary>
     /// <see cref="CalculatableActivity"/> for running a macro stability inwards calculation.
     /// </summary>
-    public class MacroStabilityInwardsCalculationActivity : CalculatableActivity
+    internal class MacroStabilityInwardsCalculationActivity : CalculatableActivity
     {
         private readonly RoundedDouble normativeAssessmentLevel;
         private readonly MacroStabilityInwardsCalculation calculation;