Index: Ringtoets/Common/src/Ringtoets.Common.IO/Resources/StochastSchema.xsd
===================================================================
diff -u -r8a00046f9112833f25944b0f2631c7003f7a1692 -rc0daad5cf902e4d8ee557ac2d09d477c19409bf7
--- Ringtoets/Common/src/Ringtoets.Common.IO/Resources/StochastSchema.xsd	(.../StochastSchema.xsd)	(revision 8a00046f9112833f25944b0f2631c7003f7a1692)
+++ Ringtoets/Common/src/Ringtoets.Common.IO/Resources/StochastSchema.xsd	(.../StochastSchema.xsd)	(revision c0daad5cf902e4d8ee557ac2d09d477c19409bf7)
@@ -47,8 +47,11 @@
   <xs:element name="stochast">
     <xs:complexType>
       <xs:sequence>
-        <xs:element ref="verwachtingswaarde"/>
-        <xs:element ref="standaardafwijking"/>
+        <xs:element minOccurs="0" ref="verwachtingswaarde"/>
+        <xs:choice minOccurs="0">
+          <xs:element ref="standaardafwijking"/>
+          <xs:element ref="variatiecoefficient"/>
+        </xs:choice>
       </xs:sequence>
       <xs:attribute name="naam" type="nameType" use="required"/>
     </xs:complexType>
@@ -76,4 +79,11 @@
     </xs:simpleType>
   </xs:element>
 
+  <!--Element definitie voor het opgeven van een variatiecoefficient.-->
+  <xs:element name="variatiecoefficient">
+    <xs:simpleType>
+      <xs:restriction base="xs:double"/>
+    </xs:simpleType>
+  </xs:element>
+  
 </xs:schema>
\ No newline at end of file
Index: Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/Readers/GrassCoverErosionInwardsCalculationConfigurationReaderTest.cs
===================================================================
diff -u -rd0a54cbc1b0f33a350874859f97f713182a3d478 -rc0daad5cf902e4d8ee557ac2d09d477c19409bf7
--- Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/Readers/GrassCoverErosionInwardsCalculationConfigurationReaderTest.cs	(.../GrassCoverErosionInwardsCalculationConfigurationReaderTest.cs)	(revision d0a54cbc1b0f33a350874859f97f713182a3d478)
+++ Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/Readers/GrassCoverErosionInwardsCalculationConfigurationReaderTest.cs	(.../GrassCoverErosionInwardsCalculationConfigurationReaderTest.cs)	(revision c0daad5cf902e4d8ee557ac2d09d477c19409bf7)
@@ -138,12 +138,6 @@
                 yield return new TestCaseData("invalidMultipleCriticalFlowRateStochast.xml",
                                               "There is a duplicate key sequence 'overslagdebiet' for the 'uniqueStochastNameConstraint' key or unique identity constraint.")
                     .SetName("invalidMultipleCriticalFlowRateStochast");
-                yield return new TestCaseData("invalidCriticalFlowRateMissingMean.xml",
-                                              "The element 'stochast' has invalid child element 'standaardafwijking'. List of possible elements expected: 'verwachtingswaarde'.")
-                    .SetName("invalidCriticalFlowRateMissingMean");
-                yield return new TestCaseData("invalidCriticalFlowRateMissingStandardDeviation.xml",
-                                              "The element 'stochast' has incomplete content. List of possible elements expected: 'standaardafwijking'.")
-                    .SetName("invalidCriticalFlowRateMissingStandardDeviation");
 
                 yield return new TestCaseData("invalidCriticalFlowRateMeanEmpty.xml",
                                               "The 'verwachtingswaarde' element is invalid - The value '' is invalid according to its datatype 'Double'")
@@ -368,5 +362,43 @@
             Assert.IsNull(calculation.CriticalFlowRateMean);
             Assert.IsNull(calculation.CriticalFlowRateStandardDeviation);
         }
+
+        [Test]
+        public void Read_ValidConfigurationWithMissingStochastMean_ExpectedValues()
+        {
+            // Setup
+            string filePath = Path.Combine(testDirectoryPath, "validConfigurationCriticalFlowRateMissingMean.xml");
+            var reader = new GrassCoverErosionInwardsCalculationConfigurationReader(filePath);
+
+            // Call
+            IList<IReadConfigurationItem> readConfigurationItems = reader.Read().ToList();
+
+            // Assert
+            Assert.AreEqual(1, readConfigurationItems.Count);
+
+            var calculation = readConfigurationItems[0] as ReadGrassCoverErosionInwardsCalculation;
+            Assert.IsNotNull(calculation);
+            Assert.IsNull(calculation.CriticalFlowRateMean);
+            Assert.AreEqual(2.2, calculation.CriticalFlowRateStandardDeviation);
+        }
+
+        [Test]
+        public void Read_ValidConfigurationWithMissingStochastStandardDeviation_ExpectedValues()
+        {
+            // Setup
+            string filePath = Path.Combine(testDirectoryPath, "validConfigurationCriticalFlowRateMissingStandardDeviation.xml");
+            var reader = new GrassCoverErosionInwardsCalculationConfigurationReader(filePath);
+
+            // Call
+            IList<IReadConfigurationItem> readConfigurationItems = reader.Read().ToList();
+
+            // Assert
+            Assert.AreEqual(1, readConfigurationItems.Count);
+
+            var calculation = readConfigurationItems[0] as ReadGrassCoverErosionInwardsCalculation;
+            Assert.IsNotNull(calculation);
+            Assert.AreEqual(1.1, calculation.CriticalFlowRateMean);
+            Assert.IsNull(calculation.CriticalFlowRateStandardDeviation);
+        }
     }
 }
\ No newline at end of file
Fisheye: Tag c0daad5cf902e4d8ee557ac2d09d477c19409bf7 refers to a dead (removed) revision in file `Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/GrassCoverErosionInwardsCalculationConfigurationReader/invalidCriticalFlowRateMissingMean.xml'.
Fisheye: No comparison available.  Pass `N' to diff?
Fisheye: Tag c0daad5cf902e4d8ee557ac2d09d477c19409bf7 refers to a dead (removed) revision in file `Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/GrassCoverErosionInwardsCalculationConfigurationReader/invalidCriticalFlowRateMissingStandardDeviation.xml'.
Fisheye: No comparison available.  Pass `N' to diff?
Index: Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/GrassCoverErosionInwardsCalculationConfigurationReader/validConfigurationCriticalFlowRateMissingMean.xml
===================================================================
diff -u
--- Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/GrassCoverErosionInwardsCalculationConfigurationReader/validConfigurationCriticalFlowRateMissingMean.xml	(revision 0)
+++ Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/GrassCoverErosionInwardsCalculationConfigurationReader/validConfigurationCriticalFlowRateMissingMean.xml	(revision c0daad5cf902e4d8ee557ac2d09d477c19409bf7)
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuratie>
+  <berekening naam="Calculation">
+    <stochasten>
+      <stochast naam="overslagdebiet">
+        <standaardafwijking>2.2</standaardafwijking>
+      </stochast>
+    </stochasten>
+  </berekening>
+</configuratie>
\ No newline at end of file
Index: Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/GrassCoverErosionInwardsCalculationConfigurationReader/validConfigurationCriticalFlowRateMissingStandardDeviation.xml
===================================================================
diff -u
--- Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/GrassCoverErosionInwardsCalculationConfigurationReader/validConfigurationCriticalFlowRateMissingStandardDeviation.xml	(revision 0)
+++ Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/GrassCoverErosionInwardsCalculationConfigurationReader/validConfigurationCriticalFlowRateMissingStandardDeviation.xml	(revision c0daad5cf902e4d8ee557ac2d09d477c19409bf7)
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuratie>
+  <berekening naam="Calculation">
+    <stochasten>
+      <stochast naam="overslagdebiet">
+        <verwachtingswaarde>1.1</verwachtingswaarde>
+      </stochast>
+    </stochasten>
+  </berekening>
+</configuratie>
\ No newline at end of file
Index: Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/Readers/PipingCalculationConfigurationReaderTest.cs
===================================================================
diff -u -ra5c5133ec23681679e77ff31b89e6410d366f247 -rc0daad5cf902e4d8ee557ac2d09d477c19409bf7
--- Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/Readers/PipingCalculationConfigurationReaderTest.cs	(.../PipingCalculationConfigurationReaderTest.cs)	(revision a5c5133ec23681679e77ff31b89e6410d366f247)
+++ Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/Readers/PipingCalculationConfigurationReaderTest.cs	(.../PipingCalculationConfigurationReaderTest.cs)	(revision c0daad5cf902e4d8ee557ac2d09d477c19409bf7)
@@ -74,12 +74,6 @@
                 yield return new TestCaseData("invalidStochastUnknownName.xml",
                                               "The 'naam' attribute is invalid - The value 'Test' is invalid according to its datatype 'nameType' - The Enumeration constraint failed.")
                     .SetName("invalidStochastUnknownName");
-                yield return new TestCaseData("invalidStochastNoMean.xml",
-                                              "The element 'stochast' has invalid child element 'standaardafwijking'.")
-                    .SetName("invalidStochastNoMean");
-                yield return new TestCaseData("invalidStochastNoStandardDeviation.xml",
-                                              "The element 'stochast' has incomplete content.")
-                    .SetName("invalidStochastNoStandardDeviation");
                 yield return new TestCaseData("invalidStochastMultipleMean.xml",
                                               "The element 'stochast' has invalid child element 'verwachtingswaarde'.")
                     .SetName("invalidStochastMultipleMean");
@@ -374,5 +368,43 @@
             Assert.IsNull(calculation.DampingFactorExitMean);
             Assert.IsNull(calculation.DampingFactorExitStandardDeviation);
         }
+
+        [Test]
+        public void Read_ValidConfigurationWithMissingStochastMean_ExpectedValues()
+        {
+            // Setup
+            string filePath = Path.Combine(testDirectoryPath, "validConfigurationStochastNoMean.xml");
+            var reader = new PipingCalculationConfigurationReader(filePath);
+
+            // Call
+            IList<IReadConfigurationItem> readConfigurationItems = reader.Read().ToList();
+
+            // Assert
+            Assert.AreEqual(1, readConfigurationItems.Count);
+
+            var calculation = readConfigurationItems[0] as ReadPipingCalculation;
+            Assert.IsNotNull(calculation);
+            Assert.IsNull(calculation.PhreaticLevelExitMean);
+            Assert.AreEqual(0.1, calculation.PhreaticLevelExitStandardDeviation);
+        }
+
+        [Test]
+        public void Read_ValidConfigurationWithMissingStochastStandardDeviation_ExpectedValues()
+        {
+            // Setup
+            string filePath = Path.Combine(testDirectoryPath, "validConfigurationStochastNoStandardDeviation.xml");
+            var reader = new PipingCalculationConfigurationReader(filePath);
+
+            // Call
+            IList<IReadConfigurationItem> readConfigurationItems = reader.Read().ToList();
+
+            // Assert
+            Assert.AreEqual(1, readConfigurationItems.Count);
+
+            var calculation = readConfigurationItems[0] as ReadPipingCalculation;
+            Assert.IsNotNull(calculation);
+            Assert.AreEqual(0.0, calculation.PhreaticLevelExitMean);
+            Assert.IsNull(calculation.PhreaticLevelExitStandardDeviation);
+        }
     }
 }
\ No newline at end of file
Fisheye: Tag c0daad5cf902e4d8ee557ac2d09d477c19409bf7 refers to a dead (removed) revision in file `Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/test-data/PipingCalculationConfigurationReader/invalidStochastNoMean.xml'.
Fisheye: No comparison available.  Pass `N' to diff?
Fisheye: Tag c0daad5cf902e4d8ee557ac2d09d477c19409bf7 refers to a dead (removed) revision in file `Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/test-data/PipingCalculationConfigurationReader/invalidStochastNoStandardDeviation.xml'.
Fisheye: No comparison available.  Pass `N' to diff?
Index: Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/test-data/PipingCalculationConfigurationReader/validConfigurationStochastNoMean.xml
===================================================================
diff -u
--- Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/test-data/PipingCalculationConfigurationReader/validConfigurationStochastNoMean.xml	(revision 0)
+++ Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/test-data/PipingCalculationConfigurationReader/validConfigurationStochastNoMean.xml	(revision c0daad5cf902e4d8ee557ac2d09d477c19409bf7)
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuratie>
+  <berekening naam="Calculation">
+    <stochasten>
+      <stochast naam="polderpeil">
+        <standaardafwijking>0.100</standaardafwijking>
+      </stochast>
+    </stochasten>
+  </berekening>
+</configuratie>
\ No newline at end of file
Index: Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/test-data/PipingCalculationConfigurationReader/validConfigurationStochastNoStandardDeviation.xml
===================================================================
diff -u
--- Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/test-data/PipingCalculationConfigurationReader/validConfigurationStochastNoStandardDeviation.xml	(revision 0)
+++ Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/test-data/PipingCalculationConfigurationReader/validConfigurationStochastNoStandardDeviation.xml	(revision c0daad5cf902e4d8ee557ac2d09d477c19409bf7)
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuratie>
+  <berekening naam="Calculation">
+    <stochasten>
+      <stochast naam="polderpeil">
+        <verwachtingswaarde>0.000</verwachtingswaarde>
+      </stochast>
+    </stochasten>
+  </berekening>
+</configuratie>
\ No newline at end of file