Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/PipingData.cs
===================================================================
diff -u -ra950714ad9510756331d862aa35695fa0b2ed03b -r7570b93f301f4503b1c787ecdba215f41eda684a
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/PipingData.cs	(.../PipingData.cs)	(revision a950714ad9510756331d862aa35695fa0b2ed03b)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/PipingData.cs	(.../PipingData.cs)	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -1,6 +1,8 @@
 using System.Collections.Generic;
 using Core.Common.BaseDelftTools;
 
+using Ringtoets.Piping.Data.Probabilistics;
+
 namespace Ringtoets.Piping.Data
 {
     /// <summary>
@@ -23,10 +25,18 @@
             Gravity = 9.81;
             WaterKinematicViscosity = 1.33e-6;
             WhitesDragCoefficient = 0.25;
-            SandParticlesVolumicWeight = 16.5;
             WaterVolumetricWeight = 9.81;
             SellmeijerReductionFactor = 0.3;
-            DampingFactorExit = 1.0;
+
+            PhreaticLevelExit = new NormalDistribution();
+            DampingFactorExit = new LognormalDistribution { Mean = 1.0 };
+            ThicknessCoverageLayer = new LognormalDistribution();
+            SandParticlesVolumicWeight = new LognormalDistribution { Mean = 16.5 };
+            CriticalHeaveGradient = new LognormalDistribution();
+            SeepageLength = new LognormalDistribution();
+            Diameter70 = new LognormalDistribution();
+            DarcyPermeability = new LognormalDistribution();
+            ThicknessAquiferLayer = new LognormalDistribution();
         }
 
         /// <summary>
@@ -35,11 +45,6 @@
         public string Name { get; set; }
 
         /// <summary>
-        /// Gets or sets the damping factor at the exit point.
-        /// </summary>
-        public double DampingFactorExit { get; set; }
-
-        /// <summary>
         /// Gets or sets the reduction factor Sellmeijer.
         /// </summary>
         public double SellmeijerReductionFactor { get; set; }
@@ -51,12 +56,6 @@
         public double WaterVolumetricWeight { get; set; }
 
         /// <summary>
-        /// Gets or sets the (lowerbound) volumic weight of sand grain material of a sand layer under water.
-        /// [kN/m&#179;]
-        /// </summary>
-        public double SandParticlesVolumicWeight { get; set; }
-
-        /// <summary>
         /// Gets or sets the White's drag coefficient.
         /// </summary>
         public double WhitesDragCoefficient { get; set; }
@@ -103,64 +102,79 @@
         public double PiezometricHeadExit { get; set; }
 
         /// <summary>
-        /// Gets or sets the phreatic level at the exit point.
-        /// [m]
-        /// </summary>
-        public double PhreaticLevelExit { get; set; }
-
-        /// <summary>
         /// Gets or sets the piezometric head in the hinterland.
         /// [m]
         /// </summary>
         public double PiezometricHeadPolder { get; set; }
 
         /// <summary>
-        /// Gets or sets the critical exit gradient for heave.
+        /// Gets or sets the calculation value used to account for uncertainty in the model for Sellmeijer.
         /// </summary>
-        public double CriticalHeaveGradient { get; set; }
+        public double SellmeijerModelFactor { get; set; }
 
         /// <summary>
-        /// Gets or sets the total thickness of the coverage layer at the exit point.
+        /// Gets or sets the x coordinate of the exit point.
         /// [m]
         /// </summary>
-        public double ThicknessCoverageLayer { get; set; }
+        public double ExitPointXCoordinate { get; set; }
 
+        #region Probabilistic parameters
+
         /// <summary>
-        /// Gets or sets the calculation value used to account for uncertainty in the model for Sellmeijer.
+        /// Gets or sets the phreatic level at the exit point.
+        /// [m]
         /// </summary>
-        public double SellmeijerModelFactor { get; set; }
+        public NormalDistribution PhreaticLevelExit { get; set; }
 
         /// <summary>
         /// Gets or sets the horizontal distance between entree and exit point.
         /// [m]
         /// </summary>
-        public double SeepageLength { get; set; }
+        public LognormalDistribution SeepageLength { get; set; }
 
         /// <summary>
         /// Gets or sets the sieve size through which 70% fraction of the grains of the top part of the aquifer passes.
         /// [m]
         /// </summary>
-        public double Diameter70 { get; set; }
+        public LognormalDistribution Diameter70 { get; set; }
 
         /// <summary>
         /// Gets or sets the Darcy-speed with which water flows through the aquifer layer.
         /// [m/s]
         /// </summary>
-        public double DarcyPermeability { get; set; }
+        public LognormalDistribution DarcyPermeability { get; set; }
 
         /// <summary>
         /// Gets or sets the thickness of the aquifer layer.
         /// [m]
         /// </summary>
-        public double ThicknessAquiferLayer { get; set; }
+        public LognormalDistribution ThicknessAquiferLayer { get; set; }
 
         /// <summary>
-        /// Gets or sets the x coordinate of the exit point.
+        /// Gets or sets the critical exit gradient for heave.
+        /// </summary>
+        public LognormalDistribution CriticalHeaveGradient { get; set; }
+
+        /// <summary>
+        /// Gets or sets the total thickness of the coverage layer at the exit point.
         /// [m]
         /// </summary>
-        public double ExitPointXCoordinate { get; set; }
+        public LognormalDistribution ThicknessCoverageLayer { get; set; }
 
         /// <summary>
+        /// Gets or sets the (lowerbound) volumic weight of sand grain material of a sand layer under water.
+        /// [kN/m&#179;]
+        /// </summary>
+        public LognormalDistribution SandParticlesVolumicWeight { get; set; }
+
+        /// <summary>
+        /// Gets or sets the damping factor at the exit point.
+        /// </summary>
+        public LognormalDistribution DampingFactorExit { get; set; }
+
+        #endregion
+
+        /// <summary>
         /// Gets or sets the surface line.
         /// </summary>
         public RingtoetsPipingSurfaceLine SurfaceLine { get; set; }
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/LognormalDistribution.cs
===================================================================
diff -u
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/LognormalDistribution.cs	(revision 0)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/LognormalDistribution.cs	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -0,0 +1,48 @@
+using System;
+
+using Ringtoets.Piping.Data.Properties;
+
+namespace Ringtoets.Piping.Data.Probabilistics
+{
+    /// <summary>
+    /// Class representing a log-normal distribution.
+    /// </summary>
+    public class LognormalDistribution
+    {
+        private double standardDeviation;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="LognormalDistribution"/> class,
+        /// initialized as the standard log-normal distribution.
+        /// </summary>
+        public LognormalDistribution()
+        {
+            Mean = 0.0;
+            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
+            {
+                return standardDeviation;
+            }
+            set
+            {
+                if (value <= 0)
+                {
+                    throw new ArgumentException(Resources.NormalDistribution_StandardDeviation_Should_be_greater_then_zero);
+                }
+                standardDeviation = value;
+            }
+        }
+    }
+}
\ No newline at end of file
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/NormalDistribution.cs
===================================================================
diff -u
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/NormalDistribution.cs	(revision 0)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Probabilistics/NormalDistribution.cs	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -0,0 +1,48 @@
+using System;
+
+using Ringtoets.Piping.Data.Properties;
+
+namespace Ringtoets.Piping.Data.Probabilistics
+{
+    /// <summary>
+    /// Class representing a normal (or Gaussian) distribution.
+    /// </summary>
+    public class NormalDistribution
+    {
+        private double standardDeviation;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="NormalDistribution"/> class,
+        /// initialized as the standard normal distribution.
+        /// </summary>
+        public NormalDistribution()
+        {
+            Mean = 0.0;
+            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
+            {
+                return standardDeviation;
+            }
+            set
+            {
+                if (value <= 0)
+                {
+                    throw new ArgumentException(Resources.NormalDistribution_StandardDeviation_Should_be_greater_then_zero);
+                }
+                standardDeviation = value;
+            }
+        }
+    }
+}
\ No newline at end of file
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Properties/Resources.Designer.cs
===================================================================
diff -u -ra950714ad9510756331d862aa35695fa0b2ed03b -r7570b93f301f4503b1c787ecdba215f41eda684a
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision a950714ad9510756331d862aa35695fa0b2ed03b)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -68,5 +68,14 @@
                 return ResourceManager.GetString("Error_CannotConstructPipingSoilProfileWithoutLayers", resourceCulture);
             }
         }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Standaard afwijking (&amp;#963;) moet groter zijn dan 0..
+        /// </summary>
+        internal static string NormalDistribution_StandardDeviation_Should_be_greater_then_zero {
+            get {
+                return ResourceManager.GetString("NormalDistribution_StandardDeviation_Should_be_greater_then_zero", resourceCulture);
+            }
+        }
     }
 }
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/Properties/Resources.resx
===================================================================
diff -u -ra950714ad9510756331d862aa35695fa0b2ed03b -r7570b93f301f4503b1c787ecdba215f41eda684a
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Properties/Resources.resx	(.../Resources.resx)	(revision a950714ad9510756331d862aa35695fa0b2ed03b)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Properties/Resources.resx	(.../Resources.resx)	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -120,4 +120,7 @@
   <data name="Error_CannotConstructPipingSoilProfileWithoutLayers" xml:space="preserve">
     <value>Geen lagen gevonden voor het profiel '{0}'.</value>
   </data>
+  <data name="NormalDistribution_StandardDeviation_Should_be_greater_then_zero" xml:space="preserve">
+    <value>Standaard afwijking (&amp;#963;) 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 -ra950714ad9510756331d862aa35695fa0b2ed03b -r7570b93f301f4503b1c787ecdba215f41eda684a
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/Ringtoets.Piping.Data.csproj	(.../Ringtoets.Piping.Data.csproj)	(revision a950714ad9510756331d862aa35695fa0b2ed03b)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/Ringtoets.Piping.Data.csproj	(.../Ringtoets.Piping.Data.csproj)	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -22,7 +22,8 @@
     <UseVSHostingProcess>false</UseVSHostingProcess>
     <ErrorReport>prompt</ErrorReport>
     <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
-    <DocumentationFile></DocumentationFile>
+    <DocumentationFile>
+    </DocumentationFile>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x86'">
     <OutputPath>bin\Release\</OutputPath>
@@ -33,7 +34,8 @@
     <PlatformTarget>x86</PlatformTarget>
     <ErrorReport>prompt</ErrorReport>
     <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
-    <DocumentationFile></DocumentationFile>
+    <DocumentationFile>
+    </DocumentationFile>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="MathNet.Numerics, Version=3.8.0.0, Culture=neutral, processorArchitecture=MSIL">
@@ -54,6 +56,8 @@
     <Compile Include="PipingSoilLayer.cs" />
     <Compile Include="PipingSoilProfile.cs" />
     <Compile Include="Point2D.cs" />
+    <Compile Include="Probabilistics\LognormalDistribution.cs" />
+    <Compile Include="Probabilistics\NormalDistribution.cs" />
     <Compile Include="RingtoetsPipingSurfaceLine.cs" />
     <Compile Include="Point3D.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
Index: Ringtoets/Piping/src/Ringtoets.Piping.Forms/PropertyClasses/PipingCalculationInputsProperties.cs
===================================================================
diff -u -ra950714ad9510756331d862aa35695fa0b2ed03b -r7570b93f301f4503b1c787ecdba215f41eda684a
--- Ringtoets/Piping/src/Ringtoets.Piping.Forms/PropertyClasses/PipingCalculationInputsProperties.cs	(.../PipingCalculationInputsProperties.cs)	(revision a950714ad9510756331d862aa35695fa0b2ed03b)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Forms/PropertyClasses/PipingCalculationInputsProperties.cs	(.../PipingCalculationInputsProperties.cs)	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -101,11 +101,11 @@
         {
             get
             {
-                return data.PipingData.DampingFactorExit;
+                return data.PipingData.DampingFactorExit.Mean;
             }
             set
             {
-                data.PipingData.DampingFactorExit = value;
+                data.PipingData.DampingFactorExit.Mean = value;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -117,11 +117,11 @@
         {
             get
             {
-                return data.PipingData.PhreaticLevelExit;
+                return data.PipingData.PhreaticLevelExit.Mean;
             }
             set
             {
-                data.PipingData.PhreaticLevelExit = value;
+                data.PipingData.PhreaticLevelExit.Mean = value;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -149,11 +149,11 @@
         {
             get
             {
-                return data.PipingData.CriticalHeaveGradient;
+                return data.PipingData.CriticalHeaveGradient.Mean;
             }
             set
             {
-                data.PipingData.CriticalHeaveGradient = value;
+                data.PipingData.CriticalHeaveGradient.Mean = value;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -165,11 +165,11 @@
         {
             get
             {
-                return data.PipingData.ThicknessCoverageLayer;
+                return data.PipingData.ThicknessCoverageLayer.Mean;
             }
             set
             {
-                data.PipingData.ThicknessCoverageLayer = value;
+                data.PipingData.ThicknessCoverageLayer.Mean = value;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -213,11 +213,11 @@
         {
             get
             {
-                return data.PipingData.SeepageLength;
+                return data.PipingData.SeepageLength.Mean;
             }
             set
             {
-                data.PipingData.SeepageLength = value;
+                data.PipingData.SeepageLength.Mean = value;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -229,11 +229,11 @@
         {
             get
             {
-                return data.PipingData.SandParticlesVolumicWeight;
+                return data.PipingData.SandParticlesVolumicWeight.Mean;
             }
             set
             {
-                data.PipingData.SandParticlesVolumicWeight = value;
+                data.PipingData.SandParticlesVolumicWeight.Mean = value;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -261,11 +261,11 @@
         {
             get
             {
-                return data.PipingData.Diameter70;
+                return data.PipingData.Diameter70.Mean;
             }
             set
             {
-                data.PipingData.Diameter70 = value;
+                data.PipingData.Diameter70.Mean = value;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -277,11 +277,11 @@
         {
             get
             {
-                return data.PipingData.DarcyPermeability;
+                return data.PipingData.DarcyPermeability.Mean;
             }
             set
             {
-                data.PipingData.DarcyPermeability = value;
+                data.PipingData.DarcyPermeability.Mean = value;
                 data.PipingData.NotifyObservers();
             }
         }
@@ -325,11 +325,11 @@
         {
             get
             {
-                return data.PipingData.ThicknessAquiferLayer;
+                return data.PipingData.ThicknessAquiferLayer.Mean;
             }
             set
             {
-                data.PipingData.ThicknessAquiferLayer = value;
+                data.PipingData.ThicknessAquiferLayer.Mean = value;
                 data.PipingData.NotifyObservers();
             }
         }
Index: Ringtoets/Piping/src/Ringtoets.Piping.Service/PipingCalculationService.cs
===================================================================
diff -u -ra950714ad9510756331d862aa35695fa0b2ed03b -r7570b93f301f4503b1c787ecdba215f41eda684a
--- Ringtoets/Piping/src/Ringtoets.Piping.Service/PipingCalculationService.cs	(.../PipingCalculationService.cs)	(revision a950714ad9510756331d862aa35695fa0b2ed03b)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Service/PipingCalculationService.cs	(.../PipingCalculationService.cs)	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -86,21 +86,21 @@
                 pipingData.UpliftModelFactor,
                 pipingData.AssessmentLevel,
                 pipingData.PiezometricHeadExit,
-                pipingData.DampingFactorExit,
-                pipingData.PhreaticLevelExit,
+                pipingData.DampingFactorExit.Mean,
+                pipingData.PhreaticLevelExit.Mean,
                 pipingData.PiezometricHeadPolder,
-                pipingData.CriticalHeaveGradient,
-                pipingData.ThicknessCoverageLayer,
+                pipingData.CriticalHeaveGradient.Mean,
+                pipingData.ThicknessCoverageLayer.Mean,
                 pipingData.SellmeijerModelFactor,
                 pipingData.SellmeijerReductionFactor,
-                pipingData.SeepageLength,
-                pipingData.SandParticlesVolumicWeight,
+                pipingData.SeepageLength.Mean,
+                pipingData.SandParticlesVolumicWeight.Mean,
                 pipingData.WhitesDragCoefficient,
-                pipingData.Diameter70,
-                pipingData.DarcyPermeability,
+                pipingData.Diameter70.Mean,
+                pipingData.DarcyPermeability.Mean,
                 pipingData.WaterKinematicViscosity,
                 pipingData.Gravity,
-                pipingData.ThicknessAquiferLayer,
+                pipingData.ThicknessAquiferLayer.Mean,
                 pipingData.MeanDiameter70,
                 pipingData.BeddingAngle,
                 pipingData.ExitPointXCoordinate,
Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingDataTest.cs
===================================================================
diff -u -ra950714ad9510756331d862aa35695fa0b2ed03b -r7570b93f301f4503b1c787ecdba215f41eda684a
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingDataTest.cs	(.../PipingDataTest.cs)	(revision a950714ad9510756331d862aa35695fa0b2ed03b)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingDataTest.cs	(.../PipingDataTest.cs)	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -2,7 +2,7 @@
 using NUnit.Framework;
 using Rhino.Mocks;
 
-using Ringtoets.Piping.Data;
+using Ringtoets.Piping.Data.Probabilistics;
 
 namespace Ringtoets.Piping.Data.Test
 {
@@ -25,24 +25,44 @@
             // Assert
             Assert.AreEqual("Piping", defaultConstructed.Name);
 
-            Assert.AreEqual(0, defaultConstructed.CriticalHeaveGradient);
+            Assert.IsInstanceOf<NormalDistribution>(defaultConstructed.PhreaticLevelExit);
+            Assert.AreEqual(0, defaultConstructed.PhreaticLevelExit.Mean);
+            Assert.AreEqual(1, defaultConstructed.PhreaticLevelExit.StandardDeviation);
+
+            Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.DampingFactorExit);
+            Assert.AreEqual(1, defaultConstructed.DampingFactorExit.Mean);
+            Assert.AreEqual(1, defaultConstructed.DampingFactorExit.StandardDeviation);
+            Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.ThicknessCoverageLayer);
+            Assert.AreEqual(0, defaultConstructed.ThicknessCoverageLayer.Mean);
+            Assert.AreEqual(1, defaultConstructed.ThicknessCoverageLayer.StandardDeviation);
+            Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.SandParticlesVolumicWeight);
+            Assert.AreEqual(16.5, defaultConstructed.SandParticlesVolumicWeight.Mean);
+            Assert.AreEqual(1, defaultConstructed.SandParticlesVolumicWeight.StandardDeviation);
+            Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.CriticalHeaveGradient);
+            Assert.AreEqual(0, defaultConstructed.CriticalHeaveGradient.Mean);
+            Assert.AreEqual(1, defaultConstructed.CriticalHeaveGradient.StandardDeviation);
+            Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.SeepageLength);
+            Assert.AreEqual(0, defaultConstructed.SeepageLength.Mean);
+            Assert.AreEqual(1, defaultConstructed.SeepageLength.StandardDeviation);
+            Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.Diameter70);
+            Assert.AreEqual(0, defaultConstructed.Diameter70.Mean);
+            Assert.AreEqual(1, defaultConstructed.Diameter70.StandardDeviation);
+            Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.DarcyPermeability);
+            Assert.AreEqual(0, defaultConstructed.DarcyPermeability.Mean);
+            Assert.AreEqual(1, defaultConstructed.DarcyPermeability.StandardDeviation);
+            Assert.IsInstanceOf<LognormalDistribution>(defaultConstructed.ThicknessAquiferLayer);
+            Assert.AreEqual(0, defaultConstructed.ThicknessAquiferLayer.Mean);
+            Assert.AreEqual(1, defaultConstructed.ThicknessAquiferLayer.StandardDeviation);
+
             Assert.AreEqual(0, defaultConstructed.UpliftModelFactor);
             Assert.AreEqual(0, defaultConstructed.PiezometricHeadExit);
             Assert.AreEqual(0, defaultConstructed.PiezometricHeadPolder);
-            Assert.AreEqual(0, defaultConstructed.ThicknessCoverageLayer);
-            Assert.AreEqual(0, defaultConstructed.PhreaticLevelExit);
             Assert.AreEqual(0, defaultConstructed.AssessmentLevel);
             Assert.AreEqual(0, defaultConstructed.SellmeijerModelFactor);
-            Assert.AreEqual(0, defaultConstructed.SeepageLength);
-            Assert.AreEqual(0, defaultConstructed.Diameter70);
-            Assert.AreEqual(0, defaultConstructed.ThicknessAquiferLayer);
-            Assert.AreEqual(0, defaultConstructed.DarcyPermeability);
             Assert.IsNull(defaultConstructed.SurfaceLine);
             Assert.IsNull(defaultConstructed.SoilProfile);
 
-            Assert.AreEqual(1.0, defaultConstructed.DampingFactorExit);
             Assert.AreEqual(0.3, defaultConstructed.SellmeijerReductionFactor);
-            Assert.AreEqual(16.5, defaultConstructed.SandParticlesVolumicWeight);
             Assert.AreEqual(9.81, defaultConstructed.Gravity);
             Assert.AreEqual(1.33e-6, defaultConstructed.WaterKinematicViscosity);
             Assert.AreEqual(9.81, defaultConstructed.WaterVolumetricWeight);
Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/LognormalDistributionTest.cs
===================================================================
diff -u
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/LognormalDistributionTest.cs	(revision 0)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/LognormalDistributionTest.cs	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -0,0 +1,39 @@
+using System;
+
+using NUnit.Framework;
+
+using Ringtoets.Piping.Data.Probabilistics;
+
+namespace Ringtoets.Piping.Data.Test.Probabilistics
+{
+    [TestFixture]
+    public class LognormalDistributionTest
+    {
+        [Test]
+        public void DefaultConstructor_ExpectedValues()
+        {
+            // Call
+            var distribution = new LognormalDistribution();
+
+            // Assert
+            Assert.AreEqual(0.0, distribution.Mean);
+            Assert.AreEqual(1.0, distribution.StandardDeviation);
+        }
+
+        [Test]
+        [TestCase(0)]
+        [TestCase(-4)]
+        public void StandardDeviation_SettingNotGreaterThan0_ThrowArgumentException(double newStd)
+        {
+            // Setup
+            var distribution = new LognormalDistribution();
+
+            // Call
+            TestDelegate call = () => distribution.StandardDeviation = newStd;
+
+            // Assert
+            ArgumentException exception = Assert.Throws<ArgumentException>(call);
+            Assert.AreEqual("Standaard afwijking (\u03C3) moet groter zijn dan 0.", exception.Message);
+        }
+    }
+}
\ No newline at end of file
Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/NormalDistributionTest.cs
===================================================================
diff -u
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/NormalDistributionTest.cs	(revision 0)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Probabilistics/NormalDistributionTest.cs	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -0,0 +1,39 @@
+using System;
+
+using NUnit.Framework;
+
+using Ringtoets.Piping.Data.Probabilistics;
+
+namespace Ringtoets.Piping.Data.Test.Probabilistics
+{
+    [TestFixture]
+    public class NomalDistributionTest
+    {
+        [Test]
+        public void DefaultConstructor_ExpectedValues()
+        {
+            // Call
+            var distribution = new NormalDistribution();
+
+            // Assert
+            Assert.AreEqual(0.0, distribution.Mean);
+            Assert.AreEqual(1.0, distribution.StandardDeviation);
+        }
+
+        [Test]
+        [TestCase(0)]
+        [TestCase(-4)]
+        public void StandardDeviation_SettingNotGreaterThan0_ThrowArgumentException(double newStd)
+        {
+            // Setup
+            var distribution = new NormalDistribution();
+
+            // Call
+            TestDelegate call = () => distribution.StandardDeviation = newStd;
+
+            // Assert
+            ArgumentException exception = Assert.Throws<ArgumentException>(call);
+            Assert.AreEqual("Standaard afwijking (\u03C3) moet groter zijn dan 0.", exception.Message);
+        }
+    }
+}
\ No newline at end of file
Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Ringtoets.Piping.Data.Test.csproj
===================================================================
diff -u -ra950714ad9510756331d862aa35695fa0b2ed03b -r7570b93f301f4503b1c787ecdba215f41eda684a
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Ringtoets.Piping.Data.Test.csproj	(.../Ringtoets.Piping.Data.Test.csproj)	(revision a950714ad9510756331d862aa35695fa0b2ed03b)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/Ringtoets.Piping.Data.Test.csproj	(.../Ringtoets.Piping.Data.Test.csproj)	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -54,6 +54,8 @@
     <Compile Include="PipingSoilLayerTest.cs" />
     <Compile Include="PipingSoilProfileTest.cs" />
     <Compile Include="Point2DTest.cs" />
+    <Compile Include="Probabilistics\LognormalDistributionTest.cs" />
+    <Compile Include="Probabilistics\NormalDistributionTest.cs" />
     <Compile Include="RingtoetsPipingSurfaceLineTest.cs" />
     <Compile Include="Point3DTest.cs" />
     <Compile Include="PointCollectionHelperTest.cs" />
Index: Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/NodePresenters/PipingCalculationInputsNodePresenterTest.cs
===================================================================
diff -u -ra950714ad9510756331d862aa35695fa0b2ed03b -r7570b93f301f4503b1c787ecdba215f41eda684a
--- Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/NodePresenters/PipingCalculationInputsNodePresenterTest.cs	(.../PipingCalculationInputsNodePresenterTest.cs)	(revision a950714ad9510756331d862aa35695fa0b2ed03b)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/NodePresenters/PipingCalculationInputsNodePresenterTest.cs	(.../PipingCalculationInputsNodePresenterTest.cs)	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -468,28 +468,28 @@
             var validPipingInput = new TestPipingInput();
             pipingData.AssessmentLevel = validPipingInput.AssessmentLevel;
             pipingData.BeddingAngle = validPipingInput.BeddingAngle;
-            pipingData.CriticalHeaveGradient = validPipingInput.CriticalHeaveGradient;
-            pipingData.DampingFactorExit = validPipingInput.DampingFactorExit;
-            pipingData.DarcyPermeability = validPipingInput.DarcyPermeability;
-            pipingData.Diameter70 = validPipingInput.Diameter70;
+            pipingData.CriticalHeaveGradient.Mean = validPipingInput.CriticalHeaveGradient;
+            pipingData.DampingFactorExit.Mean = validPipingInput.DampingFactorExit;
+            pipingData.DarcyPermeability.Mean = validPipingInput.DarcyPermeability;
+            pipingData.Diameter70.Mean = validPipingInput.Diameter70;
             pipingData.ExitPointXCoordinate = validPipingInput.ExitPointXCoordinate;
             pipingData.Gravity = validPipingInput.Gravity;
             pipingData.MeanDiameter70 = validPipingInput.MeanDiameter70;
-            pipingData.PhreaticLevelExit = validPipingInput.PhreaticLevelExit;
+            pipingData.PhreaticLevelExit.Mean = validPipingInput.PhreaticLevelExit;
             pipingData.PiezometricHeadExit = validPipingInput.PiezometricHeadExit;
             pipingData.PiezometricHeadPolder = validPipingInput.PiezometricHeadPolder;
-            pipingData.SandParticlesVolumicWeight = validPipingInput.SandParticlesVolumicWeight;
-            pipingData.SeepageLength = validPipingInput.SeepageLength;
+            pipingData.SandParticlesVolumicWeight.Mean = validPipingInput.SandParticlesVolumicWeight;
+            pipingData.SeepageLength.Mean = validPipingInput.SeepageLength;
             pipingData.SellmeijerModelFactor = validPipingInput.SellmeijerModelFactor;
             pipingData.SellmeijerReductionFactor = validPipingInput.SellmeijerReductionFactor;
-            pipingData.ThicknessAquiferLayer = validPipingInput.ThicknessAquiferLayer;
-            pipingData.ThicknessCoverageLayer = validPipingInput.ThicknessCoverageLayer;
+            pipingData.ThicknessAquiferLayer.Mean = validPipingInput.ThicknessAquiferLayer;
+            pipingData.ThicknessCoverageLayer.Mean = validPipingInput.ThicknessCoverageLayer;
             pipingData.UpliftModelFactor = validPipingInput.UpliftModelFactor;
             pipingData.WaterVolumetricWeight = validPipingInput.WaterVolumetricWeight;
             pipingData.WaterKinematicViscosity = validPipingInput.WaterKinematicViscosity;
             pipingData.WhitesDragCoefficient = validPipingInput.WhitesDragCoefficient;
             pipingData.SurfaceLine = new RingtoetsPipingSurfaceLine();
-            pipingData.SoilProfile = new PipingSoilProfile(String.Empty,random.NextDouble(), new []
+            pipingData.SoilProfile = new PipingSoilProfile(String.Empty, random.NextDouble(), new[]
             {
                 new PipingSoilLayer(1.0) 
             });
@@ -510,7 +510,7 @@
             Action action = () =>
             {
                 contextMenuAdapter.Items[calculateContextMenuItemIndex].PerformClick();
-                while(activityRunner.IsRunning)
+                while (activityRunner.IsRunning)
                 {
                     // Do something useful while waiting for calculation to finish...
                     Application.DoEvents();
Index: Ringtoets/Piping/test/Ringtoets.Piping.Service.Test/PipingCalculationActivityTest.cs
===================================================================
diff -u -ra950714ad9510756331d862aa35695fa0b2ed03b -r7570b93f301f4503b1c787ecdba215f41eda684a
--- Ringtoets/Piping/test/Ringtoets.Piping.Service.Test/PipingCalculationActivityTest.cs	(.../PipingCalculationActivityTest.cs)	(revision a950714ad9510756331d862aa35695fa0b2ed03b)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Service.Test/PipingCalculationActivityTest.cs	(.../PipingCalculationActivityTest.cs)	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -93,8 +93,8 @@
         {
             // Setup
             var validPipingData = PipingDataFactory.CreateCalculationWithValidInput();
-            validPipingData.Diameter70 = 0;
-            validPipingData.DarcyPermeability = 0;
+            validPipingData.Diameter70.Mean = 0;
+            validPipingData.DarcyPermeability.Mean = 0;
             validPipingData.Output = new TestPipingOutput();
 
             var activity = new PipingCalculationActivity(validPipingData);
Index: Ringtoets/Piping/test/Ringtoets.Piping.Service.Test/PipingCalculationServiceTest.cs
===================================================================
diff -u -ra950714ad9510756331d862aa35695fa0b2ed03b -r7570b93f301f4503b1c787ecdba215f41eda684a
--- Ringtoets/Piping/test/Ringtoets.Piping.Service.Test/PipingCalculationServiceTest.cs	(.../PipingCalculationServiceTest.cs)	(revision a950714ad9510756331d862aa35695fa0b2ed03b)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Service.Test/PipingCalculationServiceTest.cs	(.../PipingCalculationServiceTest.cs)	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -117,8 +117,8 @@
         {
             // Setup
             PipingData validPipingData = PipingDataFactory.CreateCalculationWithValidInput();
-            validPipingData.Diameter70 = 0;
-            validPipingData.DarcyPermeability = 0;
+            validPipingData.Diameter70.Mean = 0;
+            validPipingData.DarcyPermeability.Mean = 0;
 
             // Call
             var isValid = PipingCalculationService.Validate(validPipingData);
Index: Ringtoets/Piping/test/Ringtoets.Piping.Service.Test/TestHelpers/PipingDataFactory.cs
===================================================================
diff -u -ra950714ad9510756331d862aa35695fa0b2ed03b -r7570b93f301f4503b1c787ecdba215f41eda684a
--- Ringtoets/Piping/test/Ringtoets.Piping.Service.Test/TestHelpers/PipingDataFactory.cs	(.../PipingDataFactory.cs)	(revision a950714ad9510756331d862aa35695fa0b2ed03b)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Service.Test/TestHelpers/PipingDataFactory.cs	(.../PipingDataFactory.cs)	(revision 7570b93f301f4503b1c787ecdba215f41eda684a)
@@ -21,22 +21,49 @@
             {
                 AssessmentLevel = 1.0,
                 BeddingAngle = 1.0,
-                CriticalHeaveGradient = 1.0,
-                DampingFactorExit = 1.0,
-                DarcyPermeability = 1.0,
-                Diameter70 = 1.0,
+                CriticalHeaveGradient =
+                {
+                    Mean = 1.0
+                },
+                DampingFactorExit =
+                {
+                    Mean = 1.0
+                },
+                DarcyPermeability =
+                {
+                    Mean = 1.0
+                },
+                Diameter70 =
+                {
+                    Mean = 1.0
+                },
                 ExitPointXCoordinate = 1.0,
                 Gravity = 1.0,
                 MeanDiameter70 = 1.0,
                 PiezometricHeadExit = 1.0,
                 PiezometricHeadPolder = 1.0,
-                PhreaticLevelExit = 2.0,
-                SandParticlesVolumicWeight = 1.0,
-                SeepageLength = 1.0,
+                PhreaticLevelExit =
+                {
+                    Mean = 2.0
+                },
+                SandParticlesVolumicWeight =
+                {
+                    Mean = 1.0
+                },
+                SeepageLength =
+                {
+                    Mean = 1.0
+                },
                 SellmeijerModelFactor = 1.0,
                 SellmeijerReductionFactor = 1.0,
-                ThicknessAquiferLayer = 1.0,
-                ThicknessCoverageLayer = 1.0,
+                ThicknessAquiferLayer =
+                {
+                    Mean = 1.0
+                },
+                ThicknessCoverageLayer =
+                {
+                    Mean = 1.0
+                },
                 UpliftModelFactor = 1.0,
                 WaterKinematicViscosity = 1.0,
                 WaterVolumetricWeight = 1.0,