Index: Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingCalculatorExceptionTest.cs
===================================================================
diff -u -rfea3ed82dfb6dfcad535eef16efcbaa9c01564ed -r375ff37edf7bfb578e804373044eab32700f0e07
--- Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingCalculatorExceptionTest.cs	(.../PipingCalculatorExceptionTest.cs)	(revision fea3ed82dfb6dfcad535eef16efcbaa9c01564ed)
+++ Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingCalculatorExceptionTest.cs	(.../PipingCalculatorExceptionTest.cs)	(revision 375ff37edf7bfb578e804373044eab32700f0e07)
@@ -31,7 +31,8 @@
         public void DefaultConstructor_InnerExceptionNullAndMessageDefault()
         {
             // Setup
-            var expectedMessage = string.Format("Exception of type '{0}' was thrown.", typeof(PipingCalculatorException).FullName);
+            var expectedMessage = string.Format("Exception of type '{0}' was thrown.",
+                                                typeof(PipingCalculatorException).FullName);
 
             // Call
             var exception = new PipingCalculatorException();
@@ -45,7 +46,7 @@
         public void Constructor_WithCustomMessage_InnerExceptionNullAndMessageSetToCustom()
         {
             // Setup
-            var expectedMessage ="Some exception message";
+            var expectedMessage = "Some exception message";
 
             // Call
             var exception = new PipingCalculatorException(expectedMessage);
Index: Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingCalculatorTest.cs
===================================================================
diff -u -rfea3ed82dfb6dfcad535eef16efcbaa9c01564ed -r375ff37edf7bfb578e804373044eab32700f0e07
--- Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingCalculatorTest.cs	(.../PipingCalculatorTest.cs)	(revision fea3ed82dfb6dfcad535eef16efcbaa9c01564ed)
+++ Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingCalculatorTest.cs	(.../PipingCalculatorTest.cs)	(revision 375ff37edf7bfb578e804373044eab32700f0e07)
@@ -163,7 +163,7 @@
             PipingCalculatorInput input = new TestPipingInput
             {
                 PhreaticLevelExit = level,
-                PiezometricHeadExit = (RoundedDouble)level
+                PiezometricHeadExit = (RoundedDouble) level
             }.AsRealInput();
 
             var calculation = new PipingCalculator(input, PipingSubCalculatorFactory.Instance);
@@ -263,7 +263,7 @@
             // Setup
             PipingCalculatorInput input = new TestPipingInput
             {
-                AssessmentLevel = (RoundedDouble)assessmentLevel,
+                AssessmentLevel = (RoundedDouble) assessmentLevel,
                 PhreaticLevelExit = phreaticLevelExit,
                 SellmeijerReductionFactor = sellmeijerReductionFactor,
                 ThicknessCoverageLayer = thicknessCoverageLayer
@@ -316,7 +316,7 @@
             Assert.AreEqual(1, validationMessages.Count);
             Assert.AreEqual("Een ondergrondschematisatie moet geselecteerd zijn om een Uplift berekening uit te kunnen voeren.", validationMessages[0]);
         }
-        
+
         [Test]
         [TestCase(-1e-6)]
         [TestCase(0)]
@@ -328,7 +328,7 @@
             {
                 SoilProfile = new PipingSoilProfile(String.Empty, bottom, new[]
                 {
-                    new PipingSoilLayer(top) 
+                    new PipingSoilLayer(top)
                 }, SoilProfileType.SoilProfile1D, 0)
             }.AsRealInput();
 
@@ -351,7 +351,7 @@
             {
                 SoilProfile = new PipingSoilProfile(String.Empty, -1.0, new[]
                 {
-                    new PipingSoilLayer(0) 
+                    new PipingSoilLayer(0)
                 }, SoilProfileType.SoilProfile1D, 0)
             }.AsRealInput();
 
@@ -385,11 +385,11 @@
         {
             // Setup
             PipingCalculatorInput input = new TestPipingInput().AsRealInput();
-            input.SurfaceLine.SetGeometry(new []
+            input.SurfaceLine.SetGeometry(new[]
             {
-                new Point3D(0, 0, 0.5), 
-                new Point3D(1, 0, 1.5), 
-                new Point3D(2, 0, -1) 
+                new Point3D(0, 0, 0.5),
+                new Point3D(1, 0, 1.5),
+                new Point3D(2, 0, -1)
             });
 
             var calculation = new PipingCalculator(input, PipingSubCalculatorFactory.Instance);
@@ -407,7 +407,7 @@
             // Setup
             PipingCalculatorInput input = new TestPipingInput
             {
-                ExitPointXCoordinate = (RoundedDouble)2.1
+                ExitPointXCoordinate = (RoundedDouble) 2.1
             }.AsRealInput();
 
             var calculation = new PipingCalculator(input, PipingSubCalculatorFactory.Instance);
Index: Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingProfileCreatorExceptionTest.cs
===================================================================
diff -u -rfea3ed82dfb6dfcad535eef16efcbaa9c01564ed -r375ff37edf7bfb578e804373044eab32700f0e07
--- Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingProfileCreatorExceptionTest.cs	(.../PipingProfileCreatorExceptionTest.cs)	(revision fea3ed82dfb6dfcad535eef16efcbaa9c01564ed)
+++ Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingProfileCreatorExceptionTest.cs	(.../PipingProfileCreatorExceptionTest.cs)	(revision 375ff37edf7bfb578e804373044eab32700f0e07)
@@ -31,7 +31,8 @@
         public void DefaultConstructor_InnerExceptionNullAndMessageDefault()
         {
             // Setup
-            var expectedMessage = string.Format("Exception of type '{0}' was thrown.", typeof(PipingProfileCreatorException).FullName);
+            var expectedMessage = string.Format("Exception of type '{0}' was thrown.",
+                                                typeof(PipingProfileCreatorException).FullName);
 
             // Call
             var exception = new PipingProfileCreatorException();
@@ -45,7 +46,7 @@
         public void Constructor_WithCustomMessage_InnerExceptionNullAndMessageSetToCustom()
         {
             // Setup
-            var expectedMessage ="Some exception message";
+            var expectedMessage = "Some exception message";
 
             // Call
             var exception = new PipingProfileCreatorException(expectedMessage);
Index: Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingProfileCreatorTest.cs
===================================================================
diff -u -rfea3ed82dfb6dfcad535eef16efcbaa9c01564ed -r375ff37edf7bfb578e804373044eab32700f0e07
--- Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingProfileCreatorTest.cs	(.../PipingProfileCreatorTest.cs)	(revision fea3ed82dfb6dfcad535eef16efcbaa9c01564ed)
+++ Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingProfileCreatorTest.cs	(.../PipingProfileCreatorTest.cs)	(revision 375ff37edf7bfb578e804373044eab32700f0e07)
@@ -41,12 +41,12 @@
             var expectedBottom = expectedTop - random.NextDouble();
             const long pipingSoilProfileId = 1234L;
 
-            IEnumerable<PipingSoilLayer> layers = new[]
+            var layers = new[]
             {
                 new PipingSoilLayer(expectedTop)
                 {
                     IsAquifer = true
-                },
+                }
             };
             var soilProfile = new PipingSoilProfile(String.Empty, expectedBottom, layers, SoilProfileType.SoilProfile1D, pipingSoilProfileId);
 
@@ -77,7 +77,7 @@
             var expectedTopC = expectedTopB - random.NextDouble();
             var expectedBottom = expectedTopC - random.NextDouble();
             const long pipingSoilProfileId = 1234L;
-            IEnumerable<PipingSoilLayer> layers = new[]
+            var layers = new[]
             {
                 new PipingSoilLayer(expectedTopA)
                 {
@@ -121,7 +121,7 @@
             var expectedTopC = random.NextDouble() + expectedTopB;
             var expectedBottom = expectedTopA - random.NextDouble();
             const long pipingSoilProfileId = 1234L;
-            IEnumerable<PipingSoilLayer> layers = new[]
+            var layers = new[]
             {
                 new PipingSoilLayer(expectedTopA)
                 {
Index: Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingSemiProbabilisticDesignValueFactoryTest.cs
===================================================================
diff -u -rfea3ed82dfb6dfcad535eef16efcbaa9c01564ed -r375ff37edf7bfb578e804373044eab32700f0e07
--- Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingSemiProbabilisticDesignValueFactoryTest.cs	(.../PipingSemiProbabilisticDesignValueFactoryTest.cs)	(revision fea3ed82dfb6dfcad535eef16efcbaa9c01564ed)
+++ Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingSemiProbabilisticDesignValueFactoryTest.cs	(.../PipingSemiProbabilisticDesignValueFactoryTest.cs)	(revision 375ff37edf7bfb578e804373044eab32700f0e07)
@@ -20,6 +20,7 @@
 // All rights reserved.
 
 using NUnit.Framework;
+using Ringtoets.Common.Data.Probabilistics;
 using Ringtoets.Piping.Data;
 
 namespace Ringtoets.Piping.KernelWrapper.Test
@@ -36,7 +37,7 @@
             var inputParameters = new PipingInput(new GeneralPipingInput());
 
             // Call
-            var thicknessCoverageLayer = PipingSemiProbabilisticDesignValueFactory.GetThicknessCoverageLayer(inputParameters);
+            DesignVariable<LogNormalDistribution> thicknessCoverageLayer = PipingSemiProbabilisticDesignValueFactory.GetThicknessCoverageLayer(inputParameters);
 
             // Assert
             Assert.AreEqual(inputParameters.ThicknessCoverageLayer.Mean, thicknessCoverageLayer.Distribution.Mean);
@@ -51,7 +52,7 @@
             var inputParameters = new PipingInput(new GeneralPipingInput());
 
             // Call
-            var freaticLevelExit = PipingSemiProbabilisticDesignValueFactory.GetPhreaticLevelExit(inputParameters);
+            DesignVariable<NormalDistribution> freaticLevelExit = PipingSemiProbabilisticDesignValueFactory.GetPhreaticLevelExit(inputParameters);
 
             // Assert
             Assert.AreSame(inputParameters.PhreaticLevelExit, freaticLevelExit.Distribution);
@@ -65,7 +66,7 @@
             var inputParameters = new PipingInput(new GeneralPipingInput());
 
             // Call
-            var dampingFactorExit = PipingSemiProbabilisticDesignValueFactory.GetDampingFactorExit(inputParameters);
+            DesignVariable<LogNormalDistribution> dampingFactorExit = PipingSemiProbabilisticDesignValueFactory.GetDampingFactorExit(inputParameters);
 
             // Assert
             Assert.AreSame(inputParameters.DampingFactorExit, dampingFactorExit.Distribution);
@@ -83,7 +84,7 @@
             var inputParameters = new PipingInput(new GeneralPipingInput());
 
             // Call
-            var seepageLength = PipingSemiProbabilisticDesignValueFactory.GetSeepageLength(inputParameters);
+            DesignVariable<LogNormalDistribution> seepageLength = PipingSemiProbabilisticDesignValueFactory.GetSeepageLength(inputParameters);
 
             // Assert
             Assert.AreEqual(inputParameters.SeepageLength.Mean, seepageLength.Distribution.Mean);
@@ -98,7 +99,7 @@
             var inputParameters = new PipingInput(new GeneralPipingInput());
 
             // Call
-            var d70 = PipingSemiProbabilisticDesignValueFactory.GetDiameter70(inputParameters);
+            DesignVariable<LogNormalDistribution> d70 = PipingSemiProbabilisticDesignValueFactory.GetDiameter70(inputParameters);
 
             // Assert
             Assert.AreEqual(inputParameters.Diameter70.Mean, d70.Distribution.Mean);
@@ -113,7 +114,7 @@
             var inputParameters = new PipingInput(new GeneralPipingInput());
 
             // Call
-            var darcyPermeability = PipingSemiProbabilisticDesignValueFactory.GetDarcyPermeability(inputParameters);
+            DesignVariable<LogNormalDistribution> darcyPermeability = PipingSemiProbabilisticDesignValueFactory.GetDarcyPermeability(inputParameters);
 
             // Assert
             Assert.AreEqual(inputParameters.DarcyPermeability.Mean, darcyPermeability.Distribution.Mean);
@@ -128,18 +129,15 @@
             var inputParameters = new PipingInput(new GeneralPipingInput());
 
             // Call
-            var saturatedVolumicWeightOfCoverageLayer = PipingSemiProbabilisticDesignValueFactory.GetSaturatedVolumicWeightOfCoverageLayer(inputParameters);
+            DesignVariable<LogNormalDistribution> saturatedVolumicWeightOfCoverageLayer = PipingSemiProbabilisticDesignValueFactory.GetSaturatedVolumicWeightOfCoverageLayer(inputParameters);
 
             // Assert
-            Assert.AreEqual(
-                inputParameters.SaturatedVolumicWeightOfCoverageLayer.Mean, 
-                saturatedVolumicWeightOfCoverageLayer.Distribution.Mean);
-            Assert.AreEqual(
-                inputParameters.SaturatedVolumicWeightOfCoverageLayer.StandardDeviation, 
-                saturatedVolumicWeightOfCoverageLayer.Distribution.StandardDeviation);
-            Assert.AreEqual(
-                inputParameters.SaturatedVolumicWeightOfCoverageLayer.Shift, 
-                saturatedVolumicWeightOfCoverageLayer.Distribution.Shift);
+            Assert.AreEqual(inputParameters.SaturatedVolumicWeightOfCoverageLayer.Mean,
+                            saturatedVolumicWeightOfCoverageLayer.Distribution.Mean);
+            Assert.AreEqual(inputParameters.SaturatedVolumicWeightOfCoverageLayer.StandardDeviation,
+                            saturatedVolumicWeightOfCoverageLayer.Distribution.StandardDeviation);
+            Assert.AreEqual(inputParameters.SaturatedVolumicWeightOfCoverageLayer.Shift,
+                            saturatedVolumicWeightOfCoverageLayer.Distribution.Shift);
             Assert.AreEqual(0.05, saturatedVolumicWeightOfCoverageLayer.Percentile);
         }
 
@@ -150,7 +148,7 @@
             var inputParameters = new PipingInput(new GeneralPipingInput());
 
             // Call
-            var thicknessAquiferLayer = PipingSemiProbabilisticDesignValueFactory.GetThicknessAquiferLayer(inputParameters);
+            DesignVariable<LogNormalDistribution> thicknessAquiferLayer = PipingSemiProbabilisticDesignValueFactory.GetThicknessAquiferLayer(inputParameters);
 
             // Assert
             Assert.AreEqual(inputParameters.ThicknessAquiferLayer.Mean, thicknessAquiferLayer.Distribution.Mean);
Index: Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingSurfaceLineCreatorTest.cs
===================================================================
diff -u -rfea3ed82dfb6dfcad535eef16efcbaa9c01564ed -r375ff37edf7bfb578e804373044eab32700f0e07
--- Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingSurfaceLineCreatorTest.cs	(.../PipingSurfaceLineCreatorTest.cs)	(revision fea3ed82dfb6dfcad535eef16efcbaa9c01564ed)
+++ Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/PipingSurfaceLineCreatorTest.cs	(.../PipingSurfaceLineCreatorTest.cs)	(revision 375ff37edf7bfb578e804373044eab32700f0e07)
@@ -43,9 +43,9 @@
             };
             surfaceLine.SetGeometry(new[]
             {
-                new Point3D (0.0, 0.0, 1.1), 
-                new Point3D (2.2, 0.0, 3.3), 
-                new Point3D (4.4, 0.0, 5.5)
+                new Point3D(0.0, 0.0, 1.1),
+                new Point3D(2.2, 0.0, 3.3),
+                new Point3D(4.4, 0.0, 5.5)
             });
 
             // Call
@@ -64,23 +64,23 @@
         {
             // Setup
             const string name = "Local coordinate surfaceline";
+            const double firstX = 4.6;
             var surfaceLine = new RingtoetsPipingSurfaceLine
             {
                 Name = name
             };
-            const double firstX = 4.6;
             surfaceLine.SetGeometry(new[]
             {
-                new Point3D (firstX, 0.0, 1.1), 
-                new Point3D (7.8, 0.0, 3.3), 
-                new Point3D (9.9, 0.0, 5.5)
+                new Point3D(firstX, 0.0, 1.1),
+                new Point3D(7.8, 0.0, 3.3),
+                new Point3D(9.9, 0.0, 5.5)
             });
 
             // Call
             PipingSurfaceLine actual = PipingSurfaceLineCreator.Create(surfaceLine);
 
             // Assert
-            var expectedCoordinatesX = surfaceLine.Points.Select(p => p.X - firstX).ToArray();
+            double[] expectedCoordinatesX = surfaceLine.Points.Select(p => p.X - firstX).ToArray();
             Assert.AreEqual(name, actual.Name);
             CollectionAssert.AreEqual(expectedCoordinatesX, actual.Points.Select(p => p.X).ToArray(), new DoubleWithToleranceComparer(1e-2));
             CollectionAssert.AreEqual(surfaceLine.Points.Select(p => p.Y).ToArray(), actual.Points.Select(p => p.Y).ToArray());
@@ -110,7 +110,7 @@
             // Assert
             var length = Math.Sqrt(2*2 + 3*3);
             const double secondCoordinateFactor = (2.0*1.0 + 3.0*2.0)/(2.0*2.0 + 3.0*3.0);
-            var expectedCoordinatesX = new[]
+            double[] expectedCoordinatesX = 
             {
                 0.0,
                 secondCoordinateFactor*length,
@@ -141,7 +141,7 @@
             PipingSurfaceLine actual = PipingSurfaceLineCreator.Create(surfaceLine);
 
             // Assert
-            var expectedCoordinatesX = new[]
+            double[] expectedCoordinatesX = 
             {
                 0.0
             };
@@ -175,11 +175,11 @@
         {
             // Setup
             const string name = "Surfaceline without points";
+            var point = new Point3D(1.0, 1.0, 2.2);
             var surfaceLine = new RingtoetsPipingSurfaceLine
             {
                 Name = name
             };
-            var point = new Point3D(1.0, 1.0, 2.2);
             surfaceLine.SetGeometry(new[]
             {
                 point
@@ -200,11 +200,11 @@
         {
             // Setup
             const string name = "Surfaceline without points";
+            var point = new Point3D(1.0, 1.0, 2.2);
             var surfaceLine = new RingtoetsPipingSurfaceLine
             {
                 Name = name
             };
-            var point = new Point3D(1.0, 1.0, 2.2);
             surfaceLine.SetGeometry(new[]
             {
                 point
@@ -225,11 +225,11 @@
         {
             // Setup
             const string name = "Surfaceline without points";
+            var point = new Point3D(1.0, 1.0, 2.2);
             var surfaceLine = new RingtoetsPipingSurfaceLine
             {
                 Name = name
             };
-            var point = new Point3D(1.0, 1.0, 2.2);
             surfaceLine.SetGeometry(new[]
             {
                 point
@@ -250,11 +250,11 @@
         {
             // Setup
             const string name = "Surfaceline without points";
+            var point = new Point3D(1.0, 1.0, 2.2);
             var surfaceLine = new RingtoetsPipingSurfaceLine
             {
                 Name = name
             };
-            var point = new Point3D(1.0, 1.0, 2.2);
             surfaceLine.SetGeometry(new[]
             {
                 point
@@ -275,11 +275,11 @@
         {
             // Setup
             const string name = "Surfaceline without points";
+            var point = new Point3D(1.0, 1.0, 2.2);
             var surfaceLine = new RingtoetsPipingSurfaceLine
             {
                 Name = name
             };
-            var point = new Point3D(1.0, 1.0, 2.2);
             surfaceLine.SetGeometry(new[]
             {
                 point
Index: Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/SubCalculator/EffectiveThicknessCalculatorTest.cs
===================================================================
diff -u -rfea3ed82dfb6dfcad535eef16efcbaa9c01564ed -r375ff37edf7bfb578e804373044eab32700f0e07
--- Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/SubCalculator/EffectiveThicknessCalculatorTest.cs	(.../EffectiveThicknessCalculatorTest.cs)	(revision fea3ed82dfb6dfcad535eef16efcbaa9c01564ed)
+++ Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/SubCalculator/EffectiveThicknessCalculatorTest.cs	(.../EffectiveThicknessCalculatorTest.cs)	(revision 375ff37edf7bfb578e804373044eab32700f0e07)
@@ -38,6 +38,6 @@
             Assert.IsInstanceOf<IEffectiveThicknessCalculator>(calculator);
 
             Assert.Throws<NullReferenceException>(() => { var x = calculator.EffectiveHeight; });
-        } 
+        }
     }
 }
\ No newline at end of file
Index: Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/SubCalculator/PiezoHeadCalculatorTest.cs
===================================================================
diff -u -rfea3ed82dfb6dfcad535eef16efcbaa9c01564ed -r375ff37edf7bfb578e804373044eab32700f0e07
--- Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/SubCalculator/PiezoHeadCalculatorTest.cs	(.../PiezoHeadCalculatorTest.cs)	(revision fea3ed82dfb6dfcad535eef16efcbaa9c01564ed)
+++ Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/SubCalculator/PiezoHeadCalculatorTest.cs	(.../PiezoHeadCalculatorTest.cs)	(revision 375ff37edf7bfb578e804373044eab32700f0e07)
@@ -36,6 +36,6 @@
             // Assert
             Assert.IsInstanceOf<IPiezoHeadCalculator>(calculator);
             Assert.AreEqual(0.0, calculator.PhiExit);
-        } 
+        }
     }
 }
\ No newline at end of file
Index: Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/SubCalculator/PipingSubCalculatorFactoryTest.cs
===================================================================
diff -u -rfea3ed82dfb6dfcad535eef16efcbaa9c01564ed -r375ff37edf7bfb578e804373044eab32700f0e07
--- Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/SubCalculator/PipingSubCalculatorFactoryTest.cs	(.../PipingSubCalculatorFactoryTest.cs)	(revision fea3ed82dfb6dfcad535eef16efcbaa9c01564ed)
+++ Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/SubCalculator/PipingSubCalculatorFactoryTest.cs	(.../PipingSubCalculatorFactoryTest.cs)	(revision 375ff37edf7bfb578e804373044eab32700f0e07)
@@ -41,11 +41,11 @@
         [Test]
         public void Instance_WhenSetToNull_ReturnsANewInstance()
         {
-            var firstFactory = PipingSubCalculatorFactory.Instance;
+            IPipingSubCalculatorFactory firstFactory = PipingSubCalculatorFactory.Instance;
             PipingSubCalculatorFactory.Instance = null;
 
             // Call
-            var secondFactory = PipingSubCalculatorFactory.Instance;
+            IPipingSubCalculatorFactory secondFactory = PipingSubCalculatorFactory.Instance;
 
             // Assert
             Assert.AreNotSame(firstFactory, secondFactory);
@@ -59,7 +59,7 @@
             PipingSubCalculatorFactory.Instance = firstFactory;
 
             // Call
-            var secondFactory = PipingSubCalculatorFactory.Instance;
+            IPipingSubCalculatorFactory secondFactory = PipingSubCalculatorFactory.Instance;
 
             // Assert
             Assert.AreSame(firstFactory, secondFactory);
@@ -69,10 +69,10 @@
         public void CreateHeaveCalculator_Always_NewHeaveCalculator()
         {
             // Setup
-            var factory = PipingSubCalculatorFactory.Instance;
+            IPipingSubCalculatorFactory factory = PipingSubCalculatorFactory.Instance;
 
             // Call
-            var calculator = factory.CreateHeaveCalculator();
+            IHeaveCalculator calculator = factory.CreateHeaveCalculator();
 
             // Assert
             Assert.IsInstanceOf<IHeaveCalculator>(calculator);
@@ -82,10 +82,10 @@
         public void CreateUpliftCalculator_Always_NewUpliftCalculator()
         {
             // Setup
-            var factory = PipingSubCalculatorFactory.Instance;
+            IPipingSubCalculatorFactory factory = PipingSubCalculatorFactory.Instance;
 
             // Call
-            var calculator = factory.CreateUpliftCalculator();
+            IUpliftCalculator calculator = factory.CreateUpliftCalculator();
 
             // Assert
             Assert.IsInstanceOf<IUpliftCalculator>(calculator);
@@ -95,10 +95,10 @@
         public void CreateSellmeijerCalculator_Always_NewSellmeijerCalculator()
         {
             // Setup
-            var factory = PipingSubCalculatorFactory.Instance;
+            IPipingSubCalculatorFactory factory = PipingSubCalculatorFactory.Instance;
 
             // Call
-            var calculator = factory.CreateSellmeijerCalculator();
+            ISellmeijerCalculator calculator = factory.CreateSellmeijerCalculator();
 
             // Assert
             Assert.IsInstanceOf<ISellmeijerCalculator>(calculator);
@@ -108,10 +108,10 @@
         public void CreateEffectiveThicknessCalculator_Always_NewSellmeijerCalculator()
         {
             // Setup
-            var factory = PipingSubCalculatorFactory.Instance;
+            IPipingSubCalculatorFactory factory = PipingSubCalculatorFactory.Instance;
 
             // Call
-            var calculator = factory.CreateEffectiveThicknessCalculator();
+            IEffectiveThicknessCalculator calculator = factory.CreateEffectiveThicknessCalculator();
 
             // Assert
             Assert.IsInstanceOf<IEffectiveThicknessCalculator>(calculator);
@@ -121,10 +121,10 @@
         public void CreatPiezometricHeadAtExitCalculator_Always_NewPizometricHeadAtExitCalculator()
         {
             // Setup
-            var factory = PipingSubCalculatorFactory.Instance;
+            IPipingSubCalculatorFactory factory = PipingSubCalculatorFactory.Instance;
 
             // Call
-            var calculator = factory.CreatePiezometricHeadAtExitCalculator();
+            IPiezoHeadCalculator calculator = factory.CreatePiezometricHeadAtExitCalculator();
 
             // Assert
             Assert.IsInstanceOf<IPiezoHeadCalculator>(calculator);
Index: Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/SubCalculator/SellmeijerCalculatorTest.cs
===================================================================
diff -u -rfea3ed82dfb6dfcad535eef16efcbaa9c01564ed -r375ff37edf7bfb578e804373044eab32700f0e07
--- Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/SubCalculator/SellmeijerCalculatorTest.cs	(.../SellmeijerCalculatorTest.cs)	(revision fea3ed82dfb6dfcad535eef16efcbaa9c01564ed)
+++ Ringtoets/Piping/test/Ringtoets.Piping.KernelWrapper.Test/SubCalculator/SellmeijerCalculatorTest.cs	(.../SellmeijerCalculatorTest.cs)	(revision 375ff37edf7bfb578e804373044eab32700f0e07)
@@ -37,6 +37,6 @@
             Assert.IsInstanceOf<ISellmeijerCalculator>(calculator);
             Assert.AreEqual(0.0, calculator.Zp);
             Assert.AreEqual(0.0, calculator.FoSp);
-        } 
+        }
     }
 }
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