Index: Ringtoets/Piping/src/Ringtoets.Piping.Calculation/Piping/PipingSemiProbabilisticDesignValueFactory.cs
===================================================================
diff -u -rc921a50a3d1e0e6bfceff4fdff0b27705825af11 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/src/Ringtoets.Piping.Calculation/Piping/PipingSemiProbabilisticDesignValueFactory.cs	(.../PipingSemiProbabilisticDesignValueFactory.cs)	(revision c921a50a3d1e0e6bfceff4fdff0b27705825af11)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Calculation/Piping/PipingSemiProbabilisticDesignValueFactory.cs	(.../PipingSemiProbabilisticDesignValueFactory.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -13,34 +13,25 @@
         /// <summary>
         /// Creates the design variable for <see cref="PipingData.ThicknessCoverageLayer"/>.
         /// </summary>
-        public static DesignVariable GetThicknessCoverageLayer(PipingData pipingData)
+        public static DesignVariable<LognormalDistribution> GetThicknessCoverageLayer(PipingData pipingData)
         {
-            return new DesignVariable(pipingData.ThicknessCoverageLayer)
-            {
-                Percentile = 0.05
-            };
+            return CreateDesignVariable(pipingData.ThicknessCoverageLayer, 0.05);
         }
 
         /// <summary>
         /// Creates the design variable for <see cref="PipingData.PhreaticLevelExit"/>.
         /// </summary>
-        public static DesignVariable GetPhreaticLevelExit(PipingData pipingData)
+        public static DesignVariable<NormalDistribution> GetPhreaticLevelExit(PipingData pipingData)
         {
-            return new DesignVariable(pipingData.PhreaticLevelExit)
-            {
-                Percentile = 0.05
-            };
+            return CreateDesignVariable(pipingData.PhreaticLevelExit, 0.05);
         }
 
         /// <summary>
         /// Creates the design variable for <see cref="PipingData.DampingFactorExit"/>.
         /// </summary>
-        public static DesignVariable GetDampingFactorExit(PipingData pipingData)
+        public static DesignVariable<LognormalDistribution> GetDampingFactorExit(PipingData pipingData)
         {
-            return new DesignVariable(pipingData.DampingFactorExit)
-            {
-                Percentile = 0.95
-            };
+            return CreateDesignVariable(pipingData.DampingFactorExit, 0.95);
         }
 
         #endregion
@@ -50,47 +41,51 @@
         /// <summary>
         /// Creates the design variable for <see cref="PipingData.SeepageLength"/>.
         /// </summary>
-        public static DesignVariable GetSeepageLength(PipingData pipingData)
+        public static DesignVariable<LognormalDistribution> GetSeepageLength(PipingData pipingData)
         {
-            return new DesignVariable(pipingData.SeepageLength)
-            {
-                Percentile = 0.05
-            };
+            return CreateDesignVariable(pipingData.SeepageLength, 0.05);
         }
 
         /// <summary>
         /// Creates the design variable for <see cref="PipingData.Diameter70"/>.
         /// </summary>
-        public static DesignVariable GetDiameter70(PipingData pipingData)
+        public static DesignVariable<LognormalDistribution> GetDiameter70(PipingData pipingData)
         {
-            return new DesignVariable(pipingData.Diameter70)
-            {
-                Percentile = 0.05
-            };
+            return CreateDesignVariable(pipingData.Diameter70, 0.05);
         }
 
         /// <summary>
         /// Creates the design variable for <see cref="PipingData.DarcyPermeability"/>.
         /// </summary>
-        public static DesignVariable GetDarcyPermeability(PipingData pipingData)
+        public static DesignVariable<LognormalDistribution> GetDarcyPermeability(PipingData pipingData)
         {
-            return new DesignVariable(pipingData.DarcyPermeability)
-            {
-                Percentile = 0.95
-            };
+            return CreateDesignVariable(pipingData.DarcyPermeability, 0.95);
         }
 
         /// <summary>
         /// Creates the design variable for <see cref="PipingData.ThicknessAquiferLayer"/>.
         /// </summary>
-        public static DesignVariable GetThicknessAquiferLayer(PipingData pipingData)
+        public static DesignVariable<LognormalDistribution> GetThicknessAquiferLayer(PipingData pipingData)
         {
-            return new DesignVariable(pipingData.ThicknessAquiferLayer)
+            return CreateDesignVariable(pipingData.ThicknessAquiferLayer, 0.95);
+        }
+
+        #endregion
+
+        private static DesignVariable<NormalDistribution> CreateDesignVariable(NormalDistribution distribution, double percentile)
+        {
+            return new NormalDistributionDesignVariable(distribution)
             {
-                Percentile = 0.95
+                Percentile = percentile
             };
         }
 
-        #endregion
+        private static DesignVariable<LognormalDistribution> CreateDesignVariable(LognormalDistribution distribution, double percentile)
+        {
+            return new LognormalDistributionDesignVariable(distribution)
+            {
+                Percentile = percentile
+            };
+        }
     }
 }
\ No newline at end of file
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/DesignVariable.cs
===================================================================
diff -u -rc921a50a3d1e0e6bfceff4fdff0b27705825af11 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/DesignVariable.cs	(.../DesignVariable.cs)	(revision c921a50a3d1e0e6bfceff4fdff0b27705825af11)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/DesignVariable.cs	(.../DesignVariable.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -8,17 +8,17 @@
     /// This class is a representation of a variable derived from a probabilistic distribution,
     /// based on a percentile.
     /// </summary>
-    public class DesignVariable
+    public abstract class DesignVariable<DistributionType> where DistributionType : IDistribution
     {
         private double percentile;
-        private IDistribution distribution;
+        private DistributionType distribution;
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="DesignVariable"/> class with 
+        /// Initializes a new instance of the <see cref="DesignVariable{T}"/> class with 
         /// <see cref="Percentile"/> equal to 0.5.
         /// </summary>
         /// <exception cref="ArgumentNullException"><see cref="Distribution"/> is null.</exception>
-        public DesignVariable(IDistribution distribution)
+        protected DesignVariable(DistributionType distribution)
         {
             Distribution = distribution;
             percentile = 0.5;
@@ -28,7 +28,7 @@
         /// Gets or sets the probabilistic distribution of the parameter being modeled.
         /// </summary>
         /// <exception cref="ArgumentNullException"><paramref name="value"/> is null.</exception>
-        public IDistribution Distribution
+        public DistributionType Distribution
         {
             get
             {
@@ -67,9 +67,6 @@
         /// Gets the design value based on the <see cref="Distribution"/> and <see cref="Percentile"/>.
         /// </summary>
         /// <returns>A design value.</returns>
-        public double GetDesignValue()
-        {
-            return Distribution.InverseCDF(Percentile);
-        }
+        public abstract double GetDesignValue();
     }
 }
\ No newline at end of file
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/IDistribution.cs
===================================================================
diff -u -r5d53c93d9e66f38ca73d333f85855ec815f962c5 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/IDistribution.cs	(.../IDistribution.cs)	(revision 5d53c93d9e66f38ca73d333f85855ec815f962c5)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/IDistribution.cs	(.../IDistribution.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -8,12 +8,14 @@
     public interface IDistribution
     {
         /// <summary>
-        /// Performs the inverse Cumulative Density Function on the distribution, returning 
-        /// the concrete realization corresponding with the given probability.
+        /// Gets or sets the mean (expected value, E(X)) of the distribution.
         /// </summary>
-        /// <param name="p">The probability, for which P(X&lt;x) applies where x will be the returned result.</param>
-        /// <returns>The concrete realization value.</returns>
-        /// <exception cref="ArgumentOutOfRangeException"><paramref name="p"/> is not in the range [0.0, 1.0].</exception>
-        double InverseCDF(double p);
+        double Mean { get; set; }
+
+        /// <summary>
+        /// Gets or sets the standard deviation (square root of the Var(X)) of the distribution.
+        /// </summary>
+        /// <exception cref="ArgumentOutOfRangeException">Standard deviation is less then or equal to 0.</exception>
+        double StandardDeviation { get; set; }
     }
 }
\ No newline at end of file
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/LognormalDistribution.cs
===================================================================
diff -u -rc921a50a3d1e0e6bfceff4fdff0b27705825af11 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/LognormalDistribution.cs	(.../LognormalDistribution.cs)	(revision c921a50a3d1e0e6bfceff4fdff0b27705825af11)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/LognormalDistribution.cs	(.../LognormalDistribution.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -1,7 +1,5 @@
 using System;
 
-using MathNet.Numerics.Distributions;
-
 using Ringtoets.Piping.Data.Properties;
 
 namespace Ringtoets.Piping.Data.Probabilistics
@@ -12,48 +10,53 @@
     public class LognormalDistribution : IDistribution
     {
         private double standardDeviation;
+        private double mean;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="LognormalDistribution"/> class,
-        /// initialized as the standard log-normal distribution.
+        /// initialized as the standard log-normal distribution (mu=0, sigma=1).
         /// </summary>
         public LognormalDistribution()
         {
-            Mean = 0.0;
-            StandardDeviation = 1.0;
+            // Simplified calculation mean and standard deviation given mu=0 and sigma=1.
+            mean = Math.Exp(-0.5);
+            StandardDeviation = Math.Sqrt((Math.Exp(1) - 1) * Math.Exp(1));
         }
 
         /// <summary>
-        /// Gets or sets the mean (&#956;) of the distribution.
+        /// Gets or sets the mean (expected value, E(X)) of the distribution.
         /// </summary>
-        public double Mean { get; set; }
-
-        /// <summary>
-        /// Gets or sets the standard deviation (&#963;) of the distribution.
-        /// </summary>
-        public double StandardDeviation
+        /// <exception cref="ArgumentOutOfRangeException">Expected value is less then or equal to 0.</exception>
+        public double Mean
         {
             get
             {
-                return standardDeviation;
+                return mean;
             }
             set
             {
                 if (value <= 0)
                 {
-                    throw new ArgumentException(Resources.StandardDeviation_Should_be_greater_than_zero);
+                    throw new ArgumentOutOfRangeException("value", Resources.LognormalDistribution_Mean_must_be_greater_equal_to_zero);
                 }
-                standardDeviation = value;
+                mean = value;
             }
         }
 
-        public virtual double InverseCDF(double p)
+        public double StandardDeviation
         {
-            if (p < 0.0 || p > 1)
+            get
             {
-                throw new ArgumentOutOfRangeException("p", Resources.IDistribution_InverseCDF_Probability_must_be_in_range);
+                return standardDeviation;
             }
-            return LogNormal.InvCDF(Mean, StandardDeviation, p);
+            set
+            {
+                if (value <= 0)
+                {
+                    throw new ArgumentOutOfRangeException("value", Resources.StandardDeviation_Should_be_greater_than_zero);
+                }
+                standardDeviation = value;
+            }
         }
     }
 }
\ No newline at end of file
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/LognormalDistributionDesignVariable.cs
===================================================================
diff -u
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/LognormalDistributionDesignVariable.cs	(revision 0)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/LognormalDistributionDesignVariable.cs	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -0,0 +1,63 @@
+using System;
+
+namespace Ringtoets.Piping.Data.Probabilistics
+{
+    /// <summary>
+    /// This class defines a design variable for a lognormal distribution.
+    /// </summary>
+    public class LognormalDistributionDesignVariable : DesignVariable<LognormalDistribution>
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="LognormalDistributionDesignVariable"/> class.
+        /// </summary>
+        /// <param name="distribution">A lognormal distribution.</param>
+        public LognormalDistributionDesignVariable(LognormalDistribution distribution) : base(distribution) {}
+
+        public override double GetDesignValue()
+        {
+            var normalSpaceDesignValue = DetermineDesignValueInNormalDistributionSpace();
+            return ProjectFromNormalToLognormalSpace(normalSpaceDesignValue);
+        }
+
+        /// <summary>
+        /// Projects <see cref="DesignVariable{DistributionType}.Distribution"/> into 'normal
+        /// distribution' space and calculates the design value for that value space.
+        /// </summary>
+        /// <returns>The design value in 'normal distribution' space.</returns>
+        /// <remarks>Design values can only be determined in 'normal distribution' space.</remarks>
+        private double DetermineDesignValueInNormalDistributionSpace()
+        {
+            var normalDistribution = CreateNormalDistributionFromLognormalDistribution();
+            var normalDistributionDesignVariable = new NormalDistributionDesignVariable(normalDistribution)
+            {
+                Percentile = Percentile
+            };
+            return normalDistributionDesignVariable.GetDesignValue();
+        }
+
+        private static double ProjectFromNormalToLognormalSpace(double normalSpaceDesignValue)
+        {
+            return Math.Exp(normalSpaceDesignValue);
+        }
+
+        /// <summary>
+        /// Determine normal distribution parameters from log-normal parameters, as
+        /// design value can only be determined in 'normal distribution' space.
+        /// Below formula's come from Tu-Delft College dictaat "b3 Probabilistisch Ontwerpen"
+        /// by ir. A.C.W.M. Vrouwenvelder and ir.J.K. Vrijling 5th reprint 1987.
+        /// </summary>
+        /// <returns>A normal distribution based on the parameters of <see cref="DesignVariable{DistributionType}.Distribution"/>.</returns>
+        private NormalDistribution CreateNormalDistributionFromLognormalDistribution()
+        {
+            double sigmaLogOverMuLog = Distribution.StandardDeviation / Distribution.Mean;
+            double sigmaNormal = Math.Sqrt(Math.Log(sigmaLogOverMuLog * sigmaLogOverMuLog + 1.0));
+            double muNormal = Math.Log(Distribution.Mean) - 0.5 * sigmaNormal * sigmaNormal;
+
+            return new NormalDistribution
+            {
+                Mean = muNormal,
+                StandardDeviation = sigmaNormal
+            };
+        }
+    }
+}
\ No newline at end of file
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/NormalDistribution.cs
===================================================================
diff -u -rc921a50a3d1e0e6bfceff4fdff0b27705825af11 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/NormalDistribution.cs	(.../NormalDistribution.cs)	(revision c921a50a3d1e0e6bfceff4fdff0b27705825af11)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/NormalDistribution.cs	(.../NormalDistribution.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -1,7 +1,5 @@
 using System;
 
-using MathNet.Numerics.Distributions;
-
 using Ringtoets.Piping.Data.Properties;
 
 namespace Ringtoets.Piping.Data.Probabilistics
@@ -23,14 +21,8 @@
             StandardDeviation = 1.0;
         }
 
-        /// <summary>
-        /// Gets or sets the mean (&#956;) of the distribution.
-        /// </summary>
         public double Mean { get; set; }
 
-        /// <summary>
-        /// Gets or sets the standard deviation (&#963;) of the distribution.
-        /// </summary>
         public double StandardDeviation
         {
             get
@@ -41,19 +33,10 @@
             {
                 if (value <= 0)
                 {
-                    throw new ArgumentException(Resources.StandardDeviation_Should_be_greater_than_zero);
+                    throw new ArgumentOutOfRangeException("value", Resources.StandardDeviation_Should_be_greater_than_zero);
                 }
                 standardDeviation = value;
             }
         }
-
-        public double InverseCDF(double p)
-        {
-            if (p < 0.0 || p > 1)
-            {
-                throw new ArgumentOutOfRangeException("p", Resources.IDistribution_InverseCDF_Probability_must_be_in_range);
-            }
-            return Normal.InvCDF(Mean, StandardDeviation, p);
-        }
     }
 }
\ No newline at end of file
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/NormalDistributionDesignVariable.cs
===================================================================
diff -u
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/NormalDistributionDesignVariable.cs	(revision 0)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/NormalDistributionDesignVariable.cs	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -0,0 +1,18 @@
+using MathNet.Numerics.Distributions;
+
+namespace Ringtoets.Piping.Data.Probabilistics
+{
+    public class NormalDistributionDesignVariable : DesignVariable<NormalDistribution>
+    {
+        public NormalDistributionDesignVariable(NormalDistribution distribution) : base(distribution) {}
+
+        public override double GetDesignValue()
+        {
+            // Design factor is determined using the 'probit function', which is the inverse
+            // CDF function of the standard normal distribution. For more information see:
+            // "Quantile function" https://en.wikipedia.org/wiki/Normal_distribution
+            var designFactor = Normal.InvCDF(0.0, 1.0, Percentile);
+            return Distribution.Mean + designFactor * Distribution.StandardDeviation;
+        }
+    }
+}
\ No newline at end of file
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/ShiftedLognormalDistribution.cs
===================================================================
diff -u -r5d53c93d9e66f38ca73d333f85855ec815f962c5 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/ShiftedLognormalDistribution.cs	(.../ShiftedLognormalDistribution.cs)	(revision 5d53c93d9e66f38ca73d333f85855ec815f962c5)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/ShiftedLognormalDistribution.cs	(.../ShiftedLognormalDistribution.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -10,10 +10,5 @@
         /// Gets or sets the shift applied to the log-normal distribution.
         /// </summary>
         public double Shift { get; set; }
-
-        public override double InverseCDF(double p)
-        {
-            return base.InverseCDF(p) + Shift;
-        }
     }
 }
\ No newline at end of file
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Properties/Resources.Designer.cs
===================================================================
diff -u -rc921a50a3d1e0e6bfceff4fdff0b27705825af11 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision c921a50a3d1e0e6bfceff4fdff0b27705825af11)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -97,6 +97,15 @@
         }
         
         /// <summary>
+        ///   Looks up a localized string similar to Gemiddelde moet groter zijn dan 0..
+        /// </summary>
+        internal static string LognormalDistribution_Mean_must_be_greater_equal_to_zero {
+            get {
+                return ResourceManager.GetString("LognormalDistribution_Mean_must_be_greater_equal_to_zero", resourceCulture);
+            }
+        }
+        
+        /// <summary>
         ///   Looks up a localized string similar to Voor het maken van een segment zijn twee punten nodig..
         /// </summary>
         internal static string Segment2D_Constructor_Segment_must_be_created_with_two_points {
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Properties/Resources.resx
===================================================================
diff -u -rc921a50a3d1e0e6bfceff4fdff0b27705825af11 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Properties/Resources.resx	(.../Resources.resx)	(revision c921a50a3d1e0e6bfceff4fdff0b27705825af11)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Properties/Resources.resx	(.../Resources.resx)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -135,4 +135,7 @@
   <data name="IDistribution_InverseCDF_Probability_must_be_in_range" xml:space="preserve">
     <value>Kans moet in het bereik van [0, 1] opgegeven worden.</value>
   </data>
+  <data name="LognormalDistribution_Mean_must_be_greater_equal_to_zero" xml:space="preserve">
+    <value>Gemiddelde moet groter zijn dan 0.</value>
+  </data>
 </root>
\ No newline at end of file
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Ringtoets.Piping.Data.csproj
===================================================================
diff -u -r2da86d14cee084c7d6bfa52136d387cdcdb0a025 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Ringtoets.Piping.Data.csproj	(.../Ringtoets.Piping.Data.csproj)	(revision 2da86d14cee084c7d6bfa52136d387cdcdb0a025)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Ringtoets.Piping.Data.csproj	(.../Ringtoets.Piping.Data.csproj)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -59,7 +59,9 @@
     <Compile Include="Probabilistics\DesignVariable.cs" />
     <Compile Include="Probabilistics\IDistribution.cs" />
     <Compile Include="Probabilistics\LognormalDistribution.cs" />
+    <Compile Include="Probabilistics\LognormalDistributionDesignVariable.cs" />
     <Compile Include="Probabilistics\NormalDistribution.cs" />
+    <Compile Include="Probabilistics\NormalDistributionDesignVariable.cs" />
     <Compile Include="Probabilistics\ShiftedLognormalDistribution.cs" />
     <Compile Include="RingtoetsPipingSurfaceLine.cs" />
     <Compile Include="Point3D.cs" />
Index: Ringtoets/Piping/src/Ringtoets.Piping.Forms/PropertyClasses/PipingCalculationInputsProperties.cs
===================================================================
diff -u -r5076e379f409c3b5ba41eb98256e3dd5d140571c -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/src/Ringtoets.Piping.Forms/PropertyClasses/PipingCalculationInputsProperties.cs	(.../PipingCalculationInputsProperties.cs)	(revision 5076e379f409c3b5ba41eb98256e3dd5d140571c)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Forms/PropertyClasses/PipingCalculationInputsProperties.cs	(.../PipingCalculationInputsProperties.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -101,15 +101,15 @@
         [ResourcesCategory(typeof(Resources), "Categories_General")]
         [ResourcesDisplayName(typeof(Resources), "PipingData_DampingFactorExit_DisplayName")]
         [ResourcesDescription(typeof(Resources), "PipingData_DampingFactorExit_Description")]
-        public DesignVariable DampingFactorExit
+        public DesignVariable<LognormalDistribution> DampingFactorExit
         {
             get
             {
                 return PipingSemiProbabilisticDesignValueFactory.GetDampingFactorExit(data.PipingData);
             }
             set
             {
-                data.PipingData.DampingFactorExit = (LognormalDistribution)value.Distribution;
+                data.PipingData.DampingFactorExit = value.Distribution;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -118,15 +118,15 @@
         [ResourcesCategory(typeof(Resources), "Categories_General")]
         [ResourcesDisplayName(typeof(Resources), "PipingData_PhreaticLevelExit_DisplayName")]
         [ResourcesDescription(typeof(Resources), "PipingData_PhreaticLevelExit_Description")]
-        public DesignVariable PhreaticLevelExit
+        public DesignVariable<NormalDistribution> PhreaticLevelExit
         {
             get
             {
                 return PipingSemiProbabilisticDesignValueFactory.GetPhreaticLevelExit(data.PipingData);
             }
             set
             {
-                data.PipingData.PhreaticLevelExit = (NormalDistribution)value.Distribution;
+                data.PipingData.PhreaticLevelExit = value.Distribution;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -162,15 +162,15 @@
         [ResourcesCategory(typeof(Resources), "Categories_General")]
         [ResourcesDisplayName(typeof(Resources), "PipingData_ThicknessCoverageLayer_DisplayName")]
         [ResourcesDescription(typeof(Resources), "PipingData_ThicknessCoverageLayer_Description")]
-        public DesignVariable ThicknessCoverageLayer
+        public DesignVariable<LognormalDistribution> ThicknessCoverageLayer
         {
             get
             {
                 return PipingSemiProbabilisticDesignValueFactory.GetThicknessCoverageLayer(data.PipingData);
             }
             set
             {
-                data.PipingData.ThicknessCoverageLayer = (LognormalDistribution)value.Distribution;
+                data.PipingData.ThicknessCoverageLayer = value.Distribution;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -211,15 +211,15 @@
         [ResourcesCategory(typeof(Resources), "Categories_General")]
         [ResourcesDisplayName(typeof(Resources), "PipingData_SeepageLength_DisplayName")]
         [ResourcesDescription(typeof(Resources), "PipingData_SeepageLength_Description")]
-        public DesignVariable SeepageLength
+        public DesignVariable<LognormalDistribution> SeepageLength
         {
             get
             {
                 return PipingSemiProbabilisticDesignValueFactory.GetSeepageLength(data.PipingData);
             }
             set
             {
-                data.PipingData.SeepageLength = (LognormalDistribution)value.Distribution;
+                data.PipingData.SeepageLength = value.Distribution;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -260,15 +260,15 @@
         [ResourcesCategory(typeof(Resources), "Categories_General")]
         [ResourcesDisplayName(typeof(Resources), "PipingData_Diameter70_DisplayName")]
         [ResourcesDescription(typeof(Resources), "PipingData_Diameter70_Description")]
-        public DesignVariable Diameter70
+        public DesignVariable<LognormalDistribution> Diameter70
         {
             get
             {
                 return PipingSemiProbabilisticDesignValueFactory.GetDiameter70(data.PipingData);
             }
             set
             {
-                data.PipingData.Diameter70 = (LognormalDistribution)value.Distribution;
+                data.PipingData.Diameter70 = value.Distribution;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -277,15 +277,15 @@
         [ResourcesCategory(typeof(Resources), "Categories_General")]
         [ResourcesDisplayName(typeof(Resources), "PipingData_DarcyPermeability_DisplayName")]
         [ResourcesDescription(typeof(Resources), "PipingData_DarcyPermeability_Description")]
-        public DesignVariable DarcyPermeability
+        public DesignVariable<LognormalDistribution> DarcyPermeability
         {
             get
             {
                 return PipingSemiProbabilisticDesignValueFactory.GetDarcyPermeability(data.PipingData);
             }
             set
             {
-                data.PipingData.DarcyPermeability = (LognormalDistribution)value.Distribution;
+                data.PipingData.DarcyPermeability = value.Distribution;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -326,15 +326,15 @@
         [ResourcesCategory(typeof(Resources), "Categories_General")]
         [ResourcesDisplayName(typeof(Resources), "PipingData_ThicknessAquiferLayer_DisplayName")]
         [ResourcesDescription(typeof(Resources), "PipingData_ThicknessAquiferLayer_Description")]
-        public DesignVariable ThicknessAquiferLayer
+        public DesignVariable<LognormalDistribution> ThicknessAquiferLayer
         {
             get
             {
                 return PipingSemiProbabilisticDesignValueFactory.GetThicknessAquiferLayer(data.PipingData);
             }
             set
             {
-                data.PipingData.ThicknessAquiferLayer = (LognormalDistribution)value.Distribution;
+                data.PipingData.ThicknessAquiferLayer = value.Distribution;
                 data.PipingData.NotifyObservers();
             }
         }
Index: Ringtoets/Piping/src/Ringtoets.Piping.Forms/TypeConverters/DesignVariableTypeConverter.cs
===================================================================
diff -u -rc921a50a3d1e0e6bfceff4fdff0b27705825af11 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/src/Ringtoets.Piping.Forms/TypeConverters/DesignVariableTypeConverter.cs	(.../DesignVariableTypeConverter.cs)	(revision c921a50a3d1e0e6bfceff4fdff0b27705825af11)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Forms/TypeConverters/DesignVariableTypeConverter.cs	(.../DesignVariableTypeConverter.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -25,8 +25,8 @@
         {
             if (destinationType == typeof(string))
             {
-                var designVariable = (DesignVariable)value;
-                var variablesText = string.Join(", ", Parameters.Select(p => p.GetSummary((T)designVariable.Distribution, culture)));
+                var designVariable = (DesignVariable<T>)value;
+                var variablesText = string.Join(", ", Parameters.Select(p => p.GetSummary(designVariable.Distribution, culture)));
                 return String.Format("{0} ({1})", designVariable.GetDesignValue(), variablesText);
             }
             return base.ConvertTo(context, culture, value, destinationType);
@@ -41,7 +41,7 @@
         {
             IObservable observableParent = GetObservableOwnerOfDistribution(context);
 
-            var designVariable = (DesignVariable)value;
+            var designVariable = (DesignVariable<T>)value;
             PropertyDescriptorCollection propertyDescriptorCollection = TypeDescriptor.GetProperties(designVariable.Distribution);
             var properties = new PropertyDescriptor[Parameters.Length+2];
             properties[0] = new SimpleReadonlyPropertyDescriptorItem(Resources.DesignVariableTypeConverter_DestributionType_DisplayName,
@@ -73,7 +73,7 @@
         private static PropertyDescriptor CreatePropertyDescriptor(PropertyDescriptorCollection originalProperties, ParameterDefinition<T> parameter, IObservable observableParent)
         {
             PropertyDescriptor originalMeanPropertyDescriptor = originalProperties.Find(parameter.PropertyName, false);
-            var reroutedPropertyDescriptor = new RoutedPropertyDescriptor(originalMeanPropertyDescriptor, o => ((DesignVariable)o).Distribution);
+            var reroutedPropertyDescriptor = new RoutedPropertyDescriptor(originalMeanPropertyDescriptor, o => ((DesignVariable<T>)o).Distribution);
             return new TextPropertyDescriptorDecorator(reroutedPropertyDescriptor,
                                                        parameter.Symbol,
                                                        parameter.Description)
Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingDataTest.cs
===================================================================
diff -u -r7c544bdc0a35c6f193d1e786b8c001e9977c50d1 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingDataTest.cs	(.../PipingDataTest.cs)	(revision 7c544bdc0a35c6f193d1e786b8c001e9977c50d1)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingDataTest.cs	(.../PipingDataTest.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -1,4 +1,6 @@
-using Core.Common.Base;
+using System;
+
+using Core.Common.Base;
 using NUnit.Framework;
 using Rhino.Mocks;
 using Ringtoets.Piping.Calculation.TestUtil;
@@ -29,24 +31,26 @@
             Assert.AreEqual(0, defaultConstructed.PhreaticLevelExit.Mean);
             Assert.AreEqual(1, defaultConstructed.PhreaticLevelExit.StandardDeviation);
 
+            double defaultLogNormalMean = Math.Exp(-0.5);
+            double defaultLogNormalStandardDev = Math.Sqrt((Math.Exp(1) - 1) * Math.Exp(1));
             Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.DampingFactorExit);
             Assert.AreEqual(1, defaultConstructed.DampingFactorExit.Mean);
-            Assert.AreEqual(1, defaultConstructed.DampingFactorExit.StandardDeviation);
+            Assert.AreEqual(defaultLogNormalStandardDev, defaultConstructed.DampingFactorExit.StandardDeviation);
             Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.ThicknessCoverageLayer);
-            Assert.AreEqual(0, defaultConstructed.ThicknessCoverageLayer.Mean);
-            Assert.AreEqual(1, defaultConstructed.ThicknessCoverageLayer.StandardDeviation);
+            Assert.AreEqual(defaultLogNormalMean, defaultConstructed.ThicknessCoverageLayer.Mean);
+            Assert.AreEqual(defaultLogNormalStandardDev, defaultConstructed.ThicknessCoverageLayer.StandardDeviation);
             Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.SeepageLength);
-            Assert.AreEqual(0, defaultConstructed.SeepageLength.Mean);
-            Assert.AreEqual(1, defaultConstructed.SeepageLength.StandardDeviation);
+            Assert.AreEqual(defaultLogNormalMean, defaultConstructed.SeepageLength.Mean);
+            Assert.AreEqual(defaultLogNormalStandardDev, defaultConstructed.SeepageLength.StandardDeviation);
             Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.Diameter70);
-            Assert.AreEqual(0, defaultConstructed.Diameter70.Mean);
-            Assert.AreEqual(1, defaultConstructed.Diameter70.StandardDeviation);
+            Assert.AreEqual(defaultLogNormalMean, defaultConstructed.Diameter70.Mean);
+            Assert.AreEqual(defaultLogNormalStandardDev, defaultConstructed.Diameter70.StandardDeviation);
             Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.DarcyPermeability);
-            Assert.AreEqual(0, defaultConstructed.DarcyPermeability.Mean);
-            Assert.AreEqual(1, defaultConstructed.DarcyPermeability.StandardDeviation);
+            Assert.AreEqual(defaultLogNormalMean, defaultConstructed.DarcyPermeability.Mean);
+            Assert.AreEqual(defaultLogNormalStandardDev, defaultConstructed.DarcyPermeability.StandardDeviation);
             Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.ThicknessAquiferLayer);
-            Assert.AreEqual(0, defaultConstructed.ThicknessAquiferLayer.Mean);
-            Assert.AreEqual(1, defaultConstructed.ThicknessAquiferLayer.StandardDeviation);
+            Assert.AreEqual(defaultLogNormalMean, defaultConstructed.ThicknessAquiferLayer.Mean);
+            Assert.AreEqual(defaultLogNormalStandardDev, defaultConstructed.ThicknessAquiferLayer.StandardDeviation);
 
             Assert.AreEqual(0, defaultConstructed.PiezometricHeadExit);
             Assert.AreEqual(0, defaultConstructed.PiezometricHeadPolder);
Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/DesignVariableTest.cs
===================================================================
diff -u -rc921a50a3d1e0e6bfceff4fdff0b27705825af11 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/DesignVariableTest.cs	(.../DesignVariableTest.cs)	(revision c921a50a3d1e0e6bfceff4fdff0b27705825af11)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/DesignVariableTest.cs	(.../DesignVariableTest.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -20,7 +20,7 @@
             mocks.ReplayAll();
 
             // Call
-            var designVariable = new DesignVariable(distributionMock);
+            var designVariable = new SimpleDesignVariable(distributionMock);
 
             // Assert
             Assert.AreSame(distributionMock, designVariable.Distribution);
@@ -32,7 +32,7 @@
         public void ParameteredConstructor_DistributionIsNull_ThrowArgumentNullException()
         {
             // Call
-            TestDelegate call = () => new DesignVariable(null);
+            TestDelegate call = () => new SimpleDesignVariable(null);
 
             // Assert
             var exception = Assert.Throws<ArgumentNullException>(call);
@@ -52,7 +52,7 @@
             var distributionMock = mocks.StrictMock<IDistribution>();
             mocks.ReplayAll();
 
-            var designVariable = new DesignVariable(distributionMock);
+            var designVariable = new SimpleDesignVariable(distributionMock);
 
             // Call
             TestDelegate call = () => designVariable.Percentile = invalidPercentile;
@@ -75,7 +75,7 @@
             var distributionMock = mocks.StrictMock<IDistribution>();
             mocks.ReplayAll();
 
-            var designVariable = new DesignVariable(distributionMock);
+            var designVariable = new SimpleDesignVariable(distributionMock);
 
             // Call
             designVariable.Percentile = validPercentile;
@@ -93,7 +93,7 @@
             var distributionMock = mocks.StrictMock<IDistribution>();
             mocks.ReplayAll();
 
-            var designVariable = new DesignVariable(distributionMock);
+            var designVariable = new SimpleDesignVariable(distributionMock);
 
             // Call
             TestDelegate call = () => designVariable.Distribution = null;
@@ -104,29 +104,14 @@
             Assert.AreEqual("Een kansverdeling moet opgegeven zijn om op basis van die data een rekenwaarde te bepalen.", customMessagePart);
         }
 
-        [Test]
-        public void GetDesignValue_DistributionSet_ReturnInverseCdfForGivenPercentile()
+        private class SimpleDesignVariable : DesignVariable<IDistribution>
         {
-            // Setup
-            const double percentile = 0.5;
-            const double expectedValue = 1.1;
+            public SimpleDesignVariable(IDistribution distribution) : base(distribution) {}
 
-            var mocks = new MockRepository();
-            var distribution = mocks.StrictMock<IDistribution>();
-            distribution.Expect(d => d.InverseCDF(percentile)).Return(expectedValue);
-            mocks.ReplayAll();
-
-            var designVariable = new DesignVariable(distribution)
+            public override double GetDesignValue()
             {
-                Percentile = percentile
-            };
-
-            // Call
-            var designValue = designVariable.GetDesignValue();
-
-            // Assert
-            Assert.AreEqual(expectedValue, designValue);
-            mocks.VerifyAll();
+                throw new NotImplementedException();
+            }
         }
     }
 }
\ No newline at end of file
Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/LognormalDistributionDesignVariableTest.cs
===================================================================
diff -u
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/LognormalDistributionDesignVariableTest.cs	(revision 0)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/LognormalDistributionDesignVariableTest.cs	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -0,0 +1,55 @@
+using System;
+
+using NUnit.Framework;
+
+using Ringtoets.Piping.Data.Probabilistics;
+
+namespace Ringtoets.Piping.Data.Test.Probabilistics
+{
+    [TestFixture]
+    public class LognormalDistributionDesignVariableTest
+    {
+        [Test]
+        public void ParameterdConstructor_ValidLognormalDistribution_ExpectedValues()
+        {
+            // Setup
+            var lognormalDistribution = new LognormalDistribution();
+
+            // Call
+            var designValue = new LognormalDistributionDesignVariable(lognormalDistribution);
+
+            // Assert
+            Assert.AreSame(lognormalDistribution, designValue.Distribution);
+            Assert.AreEqual(0.5, designValue.Percentile);
+        }
+
+        [Test]
+        [TestCase(75, 1, 0.05, 73.36660252)]
+        [TestCase(75, 1, 0.95, 76.65613487)]
+        [TestCase(75, 5, 0.95, 78.73383874)]
+        [TestCase(75, 5, 0.05, 71.37978448)]
+        [TestCase(1, 5, 0.5, 0.40824829)]
+        public void GetDesignVariable_ValidLognormalDistribution_ReturnExpectedValue(
+            double expectedValue, double variance, double percentile,
+            double expectedResult)
+        {
+            // Setup
+            var lognormalDistribution = new LognormalDistribution
+            {
+                Mean = expectedValue,
+                StandardDeviation = Math.Sqrt(variance)
+            };
+
+            var designVariable = new LognormalDistributionDesignVariable(lognormalDistribution)
+            {
+                Percentile = percentile
+            };
+
+            // Call
+            double result = designVariable.GetDesignValue();
+
+            // Assert
+            Assert.AreEqual(expectedResult, result, 1e-6);
+        }
+    }
+}
\ No newline at end of file
Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/LognormalDistributionTest.cs
===================================================================
diff -u -r5d53c93d9e66f38ca73d333f85855ec815f962c5 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/LognormalDistributionTest.cs	(.../LognormalDistributionTest.cs)	(revision 5d53c93d9e66f38ca73d333f85855ec815f962c5)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/LognormalDistributionTest.cs	(.../LognormalDistributionTest.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -17,73 +17,57 @@
 
             // Assert
             Assert.IsInstanceOf<IDistribution>(distribution);
-            Assert.AreEqual(0.0, distribution.Mean);
-            Assert.AreEqual(1.0, distribution.StandardDeviation);
+            Assert.AreEqual(Math.Exp(-0.5), distribution.Mean);
+            Assert.AreEqual(Math.Sqrt((Math.Exp(1)-1)*Math.Exp(1)), distribution.StandardDeviation);
         }
 
         [Test]
         [TestCase(0)]
-        [TestCase(-4)]
-        public void StandardDeviation_SettingNotGreaterThan0_ThrowArgumentException(double newStd)
+        [TestCase(-123.45)]
+        public void Mean_SettingToLessThanOrEqualTo0_ThrowArgumentOutOfRangeException(double newMean)
         {
             // Setup
             var distribution = new LognormalDistribution();
 
             // Call
-            TestDelegate call = () => distribution.StandardDeviation = newStd;
+            TestDelegate call = () => distribution.Mean = newMean;
 
             // Assert
-            ArgumentException exception = Assert.Throws<ArgumentException>(call);
-            Assert.AreEqual("Standaard afwijking (\u03C3) moet groter zijn dan 0.", exception.Message);
+            var exception = Assert.Throws<ArgumentOutOfRangeException>(call);
+            var customMessagePart = exception.Message.Split(new[]{Environment.NewLine}, StringSplitOptions.None)[0];
+            Assert.AreEqual("Gemiddelde moet groter zijn dan 0.", customMessagePart);
         }
 
         [Test]
-        [TestCase(-26749.34)]
-        [TestCase(0.0 - 1e-6)]
-        [TestCase(1.0 + 1e-6)]
-        [TestCase(5678.896432)]
-        public void InverseCDF_InvalidProbability_ThrowArgumentOutOfRangeException(double invalidProbability)
+        [TestCase(0 + 1e-6)]
+        [TestCase(156.23)]
+        public void Mean_SettingValidValue_ValueIsSet(double newMean)
         {
             // Setup
             var distribution = new LognormalDistribution();
 
             // Call
-            TestDelegate call = () => distribution.InverseCDF(invalidProbability);
+            distribution.Mean = newMean;
 
             // Assert
-            var exception = Assert.Throws<ArgumentOutOfRangeException>(call);
-            var customMessagePart = exception.Message.Split(new[]
-            {
-                Environment.NewLine
-            }, StringSplitOptions.RemoveEmptyEntries)[0];
-            Assert.AreEqual("Kans moet in het bereik van [0, 1] opgegeven worden.", customMessagePart);
+            Assert.AreEqual(newMean, distribution.Mean);
         }
 
-        /// <summary>
-        /// Test oracle has been generated using EXCEL 2010, using the LOGNORM.INV function.
-        /// </summary>
         [Test]
-        [TestCase(0, 0.0)]
-        [TestCase(0.025, 0.0402791721)]
-        [TestCase(0.25, 0.6812149047)]
-        [TestCase(0.5, 3.0041660239)]
-        [TestCase(0.75, 13.2484087440)]
-        [TestCase(0.975, 224.0615444190)]
-        [TestCase(1, double.PositiveInfinity)]
-        public void InverseCDF_ValidProbability_ReturnExpectedRealization(double probability, double expectedRealization)
+        [TestCase(0)]
+        [TestCase(-4)]
+        public void StandardDeviation_SettingNotGreaterThan0_ThrowArgumentOutOfRangeException(double newStd)
         {
             // Setup
-            var distribution = new LognormalDistribution
-            {
-                Mean = 1.1,
-                StandardDeviation = 2.2
-            };
+            var distribution = new LognormalDistribution();
 
             // Call
-            var realization = distribution.InverseCDF(probability);
+            TestDelegate call = () => distribution.StandardDeviation = newStd;
 
             // Assert
-            Assert.AreEqual(expectedRealization, realization, 1e-6);
+            ArgumentException exception = Assert.Throws<ArgumentOutOfRangeException>(call);
+            string customMessagePart = exception.Message.Split(new []{Environment.NewLine}, StringSplitOptions.None)[0];
+            Assert.AreEqual("Standaard afwijking (\u03C3) moet groter zijn dan 0.", customMessagePart);
         }
     }
 }
\ No newline at end of file
Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/NormalDistributionTest.cs
===================================================================
diff -u -r5d53c93d9e66f38ca73d333f85855ec815f962c5 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/NormalDistributionTest.cs	(.../NormalDistributionTest.cs)	(revision 5d53c93d9e66f38ca73d333f85855ec815f962c5)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/NormalDistributionTest.cs	(.../NormalDistributionTest.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -24,7 +24,7 @@
         [Test]
         [TestCase(0)]
         [TestCase(-4)]
-        public void StandardDeviation_SettingNotGreaterThan0_ThrowArgumentException(double newStd)
+        public void StandardDeviation_SettingNotGreaterThan0_ThrowArgumentOutOfRangeException(double newStd)
         {
             // Setup
             var distribution = new NormalDistribution();
@@ -33,57 +33,9 @@
             TestDelegate call = () => distribution.StandardDeviation = newStd;
 
             // Assert
-            ArgumentException exception = Assert.Throws<ArgumentException>(call);
-            Assert.AreEqual("Standaard afwijking (\u03C3) moet groter zijn dan 0.", exception.Message);
+            ArgumentException exception = Assert.Throws<ArgumentOutOfRangeException>(call);
+            string customMessagePart = exception.Message.Split(new []{Environment.NewLine}, StringSplitOptions.None)[0];
+            Assert.AreEqual("Standaard afwijking (\u03C3) moet groter zijn dan 0.", customMessagePart);
         }
-
-        [Test]
-        [TestCase(-26749.34)]
-        [TestCase(0.0 - 1e-6)]
-        [TestCase(1.0 + 1e-6)]
-        [TestCase(5678.896432)]
-        public void InverseCDF_InvalidProbability_ThrowArgumentOutOfRangeException(double invalidProbability)
-        {
-            // Setup
-            var distribution = new NormalDistribution();
-
-            // Call
-            TestDelegate call = () => distribution.InverseCDF(invalidProbability);
-
-            // Assert
-            var exception = Assert.Throws<ArgumentOutOfRangeException>(call);
-            var customMessagePart = exception.Message.Split(new[]
-            {
-                Environment.NewLine
-            }, StringSplitOptions.RemoveEmptyEntries)[0];
-            Assert.AreEqual("Kans moet in het bereik van [0, 1] opgegeven worden.", customMessagePart);
-        }
-
-        /// <summary>
-        /// Test oracle has been generated using EXCEL 2010, using the NORM.INV function.
-        /// </summary>
-        [Test]
-        [TestCase(0, double.NegativeInfinity)]
-        [TestCase(0.025, -3.2119207660)]
-        [TestCase(0.25, -0.3838774504)]
-        [TestCase(0.5, 1.1000000000)]
-        [TestCase(0.75, 2.5838774504)]
-        [TestCase(0.975, 5.4119207660)]
-        [TestCase(1, double.PositiveInfinity)]
-        public void InverseCDF_ValidProbability_ReturnExpectedRealization(double probability, double expectedRealization)
-        {
-            // Setup
-            var distribution = new NormalDistribution
-            {
-                Mean = 1.1,
-                StandardDeviation = 2.2
-            };
-
-            // Call
-            var realization = distribution.InverseCDF(probability);
-
-            // Assert
-            Assert.AreEqual(expectedRealization, realization, 1e-6);
-        }
     }
 }
\ No newline at end of file
Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/ShiftedLognormalDistributionTest.cs
===================================================================
diff -u -r5d53c93d9e66f38ca73d333f85855ec815f962c5 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/ShiftedLognormalDistributionTest.cs	(.../ShiftedLognormalDistributionTest.cs)	(revision 5d53c93d9e66f38ca73d333f85855ec815f962c5)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/ShiftedLognormalDistributionTest.cs	(.../ShiftedLognormalDistributionTest.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -1,7 +1,5 @@
-using System;
+using NUnit.Framework;
 
-using NUnit.Framework;
-
 using Ringtoets.Piping.Data.Probabilistics;
 
 namespace Ringtoets.Piping.Data.Test.Probabilistics
@@ -19,56 +17,5 @@
             Assert.IsInstanceOf<LognormalDistribution>(distribution);
             Assert.AreEqual(0.0, distribution.Shift);
         }
-
-        [Test]
-        [TestCase(-26749.34)]
-        [TestCase(0.0 - 1e-6)]
-        [TestCase(1.0 + 1e-6)]
-        [TestCase(5678.896432)]
-        public void InverseCDF_InvalidProbability_ThrowArgumentOutOfRangeException(double invalidProbability)
-        {
-            // Setup
-            var distribution = new ShiftedLognormalDistribution();
-
-            // Call
-            TestDelegate call = () => distribution.InverseCDF(invalidProbability);
-
-            // Assert
-            var exception = Assert.Throws<ArgumentOutOfRangeException>(call);
-            var customMessagePart = exception.Message.Split(new[]
-            {
-                Environment.NewLine
-            }, StringSplitOptions.RemoveEmptyEntries)[0];
-            Assert.AreEqual("Kans moet in het bereik van [0, 1] opgegeven worden.", customMessagePart);
-        }
-
-        /// <summary>
-        /// Test oracle has been generated using EXCEL 2010, using the LOGNORM.INV function,
-        /// then adding the shift to the result.
-        /// </summary>
-        [Test]
-        [TestCase(0, 3.3)]
-        [TestCase(0.025, 3.3402791721)]
-        [TestCase(0.25, 3.9812149047)]
-        [TestCase(0.5, 6.3041660239)]
-        [TestCase(0.75, 16.5484087440)]
-        [TestCase(0.975, 227.3615444190)]
-        [TestCase(1, double.PositiveInfinity)]
-        public void InverseCDF_ValidProbability_ReturnExpectedRealization(double probability, double expectedRealization)
-        {
-            // Setup
-            var distribution = new ShiftedLognormalDistribution
-            {
-                Mean = 1.1,
-                StandardDeviation = 2.2,
-                Shift = 3.3
-            };
-
-            // Call
-            var realization = distribution.InverseCDF(probability);
-
-            // Assert
-            Assert.AreEqual(expectedRealization, realization, 1e-6);
-        }
     }
 }
\ No newline at end of file
Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Ringtoets.Piping.Data.Test.csproj
===================================================================
diff -u -r78aece3188a23a908e7c0a47e53e5facd1c7edb5 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Ringtoets.Piping.Data.Test.csproj	(.../Ringtoets.Piping.Data.Test.csproj)	(revision 78aece3188a23a908e7c0a47e53e5facd1c7edb5)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Ringtoets.Piping.Data.Test.csproj	(.../Ringtoets.Piping.Data.Test.csproj)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -55,6 +55,7 @@
     <Compile Include="PipingSoilProfileTest.cs" />
     <Compile Include="Point2DTest.cs" />
     <Compile Include="Probabilistics\DesignVariableTest.cs" />
+    <Compile Include="Probabilistics\LognormalDistributionDesignVariableTest.cs" />
     <Compile Include="Probabilistics\LognormalDistributionTest.cs" />
     <Compile Include="Probabilistics\NormalDistributionTest.cs" />
     <Compile Include="Probabilistics\ShiftedLognormalDistributionTest.cs" />
Index: Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/PropertyClasses/PipingCalculationInputsPropertiesTest.cs
===================================================================
diff -u -r1efcd2277f5a38d44a78e4a9286eec35134fe8dd -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/PropertyClasses/PipingCalculationInputsPropertiesTest.cs	(.../PipingCalculationInputsPropertiesTest.cs)	(revision 1efcd2277f5a38d44a78e4a9286eec35134fe8dd)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/PropertyClasses/PipingCalculationInputsPropertiesTest.cs	(.../PipingCalculationInputsPropertiesTest.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -140,13 +140,13 @@
             double meanDiameter70 = random.NextDouble();
             double beddingAngle = random.NextDouble();
 
-            IDistribution dampingFactorExit = new LognormalDistribution();
-            IDistribution phreaticLevelExit = new NormalDistribution();
-            IDistribution thicknessCoverageLayer = new LognormalDistribution();
-            IDistribution seepageLength = new LognormalDistribution();
-            IDistribution diameter70 = new LognormalDistribution();
-            IDistribution darcyPermeability = new LognormalDistribution();
-            IDistribution thicknessAquiferLayer = new LognormalDistribution();
+            var dampingFactorExit = new LognormalDistribution();
+            var phreaticLevelExit = new NormalDistribution();
+            var thicknessCoverageLayer = new LognormalDistribution();
+            var seepageLength = new LognormalDistribution();
+            var diameter70 = new LognormalDistribution();
+            var darcyPermeability = new LognormalDistribution();
+            var thicknessAquiferLayer = new LognormalDistribution();
 
             RingtoetsPipingSurfaceLine surfaceLine = new RingtoetsPipingSurfaceLine();
             PipingSoilProfile soilProfile = new TestPipingSoilProfile();
@@ -162,20 +162,20 @@
                 WaterVolumetricWeight = waterVolumetricWeight,
                 UpliftModelFactor = upliftModelFactor,
                 PiezometricHeadExit = piezometricHeadExit,
-                DampingFactorExit = new DesignVariable(dampingFactorExit),
-                PhreaticLevelExit = new DesignVariable(phreaticLevelExit),
+                DampingFactorExit = new LognormalDistributionDesignVariable(dampingFactorExit),
+                PhreaticLevelExit = new NormalDistributionDesignVariable(phreaticLevelExit),
                 PiezometricHeadPolder = piezometricHeadPolder,
-                ThicknessCoverageLayer = new DesignVariable(thicknessCoverageLayer),
+                ThicknessCoverageLayer = new LognormalDistributionDesignVariable(thicknessCoverageLayer),
                 SellmeijerModelFactor = sellmeijerModelFactor,
                 SellmeijerReductionFactor = sellmeijerReductionFactor,
-                SeepageLength = new DesignVariable(seepageLength),
+                SeepageLength = new LognormalDistributionDesignVariable(seepageLength),
                 SandParticlesVolumicWeight = sandParticlesVolumicWeight,
                 WhitesDragCoefficient = whitesDragCoefficient,
-                Diameter70 = new DesignVariable(diameter70),
-                DarcyPermeability = new DesignVariable(darcyPermeability),
+                Diameter70 = new LognormalDistributionDesignVariable(diameter70),
+                DarcyPermeability = new LognormalDistributionDesignVariable(darcyPermeability),
                 WaterKinematicViscosity = waterKinematicViscosity,
                 Gravity = gravity,
-                ThicknessAquiferLayer = new DesignVariable(thicknessAquiferLayer),
+                ThicknessAquiferLayer = new LognormalDistributionDesignVariable(thicknessAquiferLayer),
                 MeanDiameter70 = meanDiameter70,
                 BeddingAngle = beddingAngle,
                 SurfaceLine = surfaceLine,
Index: Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/Ringtoets.Piping.Forms.Test.csproj
===================================================================
diff -u -reee6c7815d1e418eac38c1c552fb279c0887ef55 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/Ringtoets.Piping.Forms.Test.csproj	(.../Ringtoets.Piping.Forms.Test.csproj)	(revision eee6c7815d1e418eac38c1c552fb279c0887ef55)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/Ringtoets.Piping.Forms.Test.csproj	(.../Ringtoets.Piping.Forms.Test.csproj)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -66,7 +66,6 @@
     <Compile Include="PropertyClasses\WtiProjectPropertiesTest.cs" />
     <Compile Include="TypeConverters\LognormalDistributionDesignVariableTypeConverterTest.cs" />
     <Compile Include="TypeConverters\PropertyDescriptors\RoutedPropertyDescriptorTest.cs" />
-    <Compile Include="TypeConverters\ShiftedLognormalDistributionDesignVariableTypeConverterTest.cs" />
     <Compile Include="TypeConverters\PropertyDescriptors\SimpleReadonlyPropertyDescriptorItemTest.cs" />
     <Compile Include="TypeConverters\PropertyDescriptors\TextPropertyDescriptorDecoratorTest.cs" />
     <Compile Include="TypeConverters\NormalDistributionDesignVariableTypeConverterTest.cs" />
Index: Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/TypeConverters/LognormalDistributionDesignVariableTypeConverterTest.cs
===================================================================
diff -u -rc921a50a3d1e0e6bfceff4fdff0b27705825af11 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/TypeConverters/LognormalDistributionDesignVariableTypeConverterTest.cs	(.../LognormalDistributionDesignVariableTypeConverterTest.cs)	(revision c921a50a3d1e0e6bfceff4fdff0b27705825af11)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/TypeConverters/LognormalDistributionDesignVariableTypeConverterTest.cs	(.../LognormalDistributionDesignVariableTypeConverterTest.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -49,7 +49,7 @@
                 Mean = 1.1,
                 StandardDeviation = 2.2
             };
-            var designVariable = new DesignVariable(distribution);
+            var designVariable = new LognormalDistributionDesignVariable(distribution);
 
             var converter = new LognormalDistributionDesignVariableTypeConverter();
 
@@ -80,7 +80,7 @@
         {
             // Setup
             var distribution = new LognormalDistribution();
-            var designVariable = new DesignVariable(distribution);
+            var designVariable = new LognormalDistributionDesignVariable(distribution);
             var converter = new LognormalDistributionDesignVariableTypeConverter();
 
             // Call
@@ -150,7 +150,7 @@
 
             pipingData.Attach(observer);
 
-            DesignVariable dampingFactorExit = calculationInputsProperties.DampingFactorExit;
+            DesignVariable<LognormalDistribution> dampingFactorExit = calculationInputsProperties.DampingFactorExit;
             var properties = new LognormalDistributionDesignVariableTypeConverter().GetProperties(typeDescriptorContextMock, dampingFactorExit);
 
             // Precondition
Index: Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/TypeConverters/NormalDistributionDesignVariableTypeConverterTest.cs
===================================================================
diff -u -rc921a50a3d1e0e6bfceff4fdff0b27705825af11 -r394db7c1bd905eb7444b9b2c47bcb5111bb63af6
--- Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/TypeConverters/NormalDistributionDesignVariableTypeConverterTest.cs	(.../NormalDistributionDesignVariableTypeConverterTest.cs)	(revision c921a50a3d1e0e6bfceff4fdff0b27705825af11)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/TypeConverters/NormalDistributionDesignVariableTypeConverterTest.cs	(.../NormalDistributionDesignVariableTypeConverterTest.cs)	(revision 394db7c1bd905eb7444b9b2c47bcb5111bb63af6)
@@ -49,7 +49,7 @@
                 Mean = 1.1,
                 StandardDeviation = 2.2
             };
-            var designVariable = new DesignVariable(distribution);
+            var designVariable = new NormalDistributionDesignVariable(distribution);
             var converter = new NormalDistributionDesignVariableTypeConverter();
 
             // Call
@@ -79,7 +79,7 @@
         {
             // Setup
             var distribution = new NormalDistribution();
-            var designVariable = new DesignVariable(distribution);
+            var designVariable = new NormalDistributionDesignVariable(distribution);
             var converter = new NormalDistributionDesignVariableTypeConverter();
 
             // Call
@@ -149,7 +149,7 @@
 
             pipingData.Attach(observer);
 
-            DesignVariable designVariable = calculationInputsProperties.PhreaticLevelExit;
+            DesignVariable<NormalDistribution> designVariable = calculationInputsProperties.PhreaticLevelExit;
             var properties = new NormalDistributionDesignVariableTypeConverter().GetProperties(typeDescriptorContextMock, designVariable);
 
             // Precondition
Fisheye: Tag 394db7c1bd905eb7444b9b2c47bcb5111bb63af6 refers to a dead (removed) revision in file `Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/TypeConverters/ShiftedLognormalDistributionDesignVariableTypeConverterTest.cs'.
Fisheye: No comparison available.  Pass `N' to diff?