Index: Riskeer/Common/src/Riskeer.Common.Data/FailureMechanism/ScenarioConfigurationPerFailureMechanismSection.cs
===================================================================
diff -u -r284cb27417263141ef138969297da216150b08a4 -rf46dff86a77c90d968fc00fc6e6306711ebf1b83
--- Riskeer/Common/src/Riskeer.Common.Data/FailureMechanism/ScenarioConfigurationPerFailureMechanismSection.cs	(.../ScenarioConfigurationPerFailureMechanismSection.cs)	(revision 284cb27417263141ef138969297da216150b08a4)
+++ Riskeer/Common/src/Riskeer.Common.Data/FailureMechanism/ScenarioConfigurationPerFailureMechanismSection.cs	(.../ScenarioConfigurationPerFailureMechanismSection.cs)	(revision f46dff86a77c90d968fc00fc6e6306711ebf1b83)
@@ -27,48 +27,56 @@
 
 namespace Riskeer.Common.Data.FailureMechanism
 {
-    
     /// <summary>
-    /// This class holds the information of the scenario configuration of the <see cref="FailureMechanismSection"/>.
+    /// This base class holds the information of the scenario configuration of the <see cref="FailureMechanismSection"/>.
     /// </summary>
-    public class ScenarioConfigurationPerFailureMechanismSection : Observable
+    public abstract class ScenarioConfigurationPerFailureMechanismSection : Observable
     {
-        private static readonly Range<double> validityRangeA = new Range<double>(0, 1);
-        private double a;
+        private const int aNrOfDecimals = 3;
 
+        private static readonly Range<RoundedDouble> validityRangeA = new Range<RoundedDouble>(
+            new RoundedDouble(aNrOfDecimals), new RoundedDouble(aNrOfDecimals, 1));
+
+        private RoundedDouble a;
+
         /// <summary>
-        /// Creates a new instance of <see cref="Riskeer.Piping.Data.PipingScenarioConfigurationPerFailureMechanismSection"/>.
+        /// Creates a new instance of <see cref="ScenarioConfigurationPerFailureMechanismSection"/>.
         /// </summary>
         /// <param name="section">The <see cref="FailureMechanismSection"/> to get the scenario configuration from.</param>
+        /// <param name="a">The 'a' parameter used to factor in the 'length effect' when determining the
+        /// maximum tolerated probability of failure.</param>
         /// <exception cref="ArgumentNullException">Thrown when <paramref name="section"/> is <c>null</c>.</exception>
-        public ScenarioConfigurationPerFailureMechanismSection(FailureMechanismSection section)
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when value is not in the range [0, 1].</exception>
+        protected ScenarioConfigurationPerFailureMechanismSection(FailureMechanismSection section, RoundedDouble a)
         {
             if (section == null)
             {
                 throw new ArgumentNullException(nameof(section));
             }
 
+            A = a;
             Section = section;
         }
-        
+
         /// <summary>
         /// Gets or sets 'a' parameter used to factor in the 'length effect' when determining the
         /// maximum tolerated probability of failure.
         /// </summary>
         /// <exception cref="ArgumentOutOfRangeException">Thrown when value is not in the range [0, 1].</exception>
-        public double A
+        public RoundedDouble A
         {
             get => a;
             set
             {
-                if (!validityRangeA.InRange(value))
+                RoundedDouble newA = value.ToPrecision(aNrOfDecimals);
+                if (!validityRangeA.InRange(newA))
                 {
                     throw new ArgumentOutOfRangeException(nameof(value),
                                                           string.Format(Resources.ProbabilityAssessmentInput_A_Value_must_be_in_Range_0_,
                                                                         validityRangeA.ToString(FormattableConstants.ShowAtLeastOneDecimal, CultureInfo.CurrentCulture)));
                 }
 
-                a = value;
+                a = newA;
             }
         }
 
Index: Riskeer/Common/test/Riskeer.Common.Data.Test/FailureMechanism/ScenarioConfigurationPerFailureMechanismSectionTest.cs
===================================================================
diff -u -r284cb27417263141ef138969297da216150b08a4 -rf46dff86a77c90d968fc00fc6e6306711ebf1b83
--- Riskeer/Common/test/Riskeer.Common.Data.Test/FailureMechanism/ScenarioConfigurationPerFailureMechanismSectionTest.cs	(.../ScenarioConfigurationPerFailureMechanismSectionTest.cs)	(revision 284cb27417263141ef138969297da216150b08a4)
+++ Riskeer/Common/test/Riskeer.Common.Data.Test/FailureMechanism/ScenarioConfigurationPerFailureMechanismSectionTest.cs	(.../ScenarioConfigurationPerFailureMechanismSectionTest.cs)	(revision f46dff86a77c90d968fc00fc6e6306711ebf1b83)
@@ -19,8 +19,8 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
-
 using System;
+using Core.Common.Base.Data;
 using Core.Common.TestUtil;
 using NUnit.Framework;
 using Riskeer.Common.Data.FailureMechanism;
@@ -34,66 +34,90 @@
         [Test]
         public void Constructor_SectionNull_ThrowsArgumentNullException()
         {
+            // Setup
+            var random = new Random(21);
+
             // Call
-            void Call() => new ScenarioConfigurationPerFailureMechanismSection(null);
+            void Call() => new TestScenarioConfigurationPerFailureMechanismSection(null, random.NextRoundedDouble());
 
             // Assert
             var exception = Assert.Throws<ArgumentNullException>(Call);
             Assert.AreEqual("section", exception.ParamName);
         }
-        
+
         [Test]
         public void Constructor_ExpectedValues()
         {
-            // Call
+            // Setup
+            var random = new Random(21);
+            RoundedDouble a = random.NextRoundedDouble();
+
             FailureMechanismSection section = FailureMechanismSectionTestFactory.CreateFailureMechanismSection();
-            
+
             // Call
-            var scenarioConfigurationPerFailureMechanismSection = new ScenarioConfigurationPerFailureMechanismSection(section);
+            var scenarioConfigurationPerFailureMechanismSection = new TestScenarioConfigurationPerFailureMechanismSection(section, a);
 
             // Assert
-            Assert.AreEqual(0, scenarioConfigurationPerFailureMechanismSection.A);
+            Assert.AreEqual(3, scenarioConfigurationPerFailureMechanismSection.A.NumberOfDecimalPlaces);
+            Assert.AreEqual(a, scenarioConfigurationPerFailureMechanismSection.A, scenarioConfigurationPerFailureMechanismSection.A.GetAccuracy());
+
             Assert.AreSame(section, scenarioConfigurationPerFailureMechanismSection.Section);
         }
-        
+
         [Test]
         [SetCulture("nl-NL")]
         [TestCase(-1)]
+        [TestCase(-0.0005)]
         [TestCase(-0.1)]
         [TestCase(1.1)]
+        [TestCase(1.0005)]
         [TestCase(8)]
         [TestCase(double.NaN)]
+        [TestCase(double.NegativeInfinity)]
+        [TestCase(double.PositiveInfinity)]
         public void A_InvalidValue_ThrowsArgumentOutOfRangeException(double a)
         {
             // Setup
+            var random = new Random(21);
+
             FailureMechanismSection section = FailureMechanismSectionTestFactory.CreateFailureMechanismSection();
-            var scenarioConfigurationPerFailureMechanismSection = new ScenarioConfigurationPerFailureMechanismSection(section);
+            var scenarioConfigurationPerFailureMechanismSection = new TestScenarioConfigurationPerFailureMechanismSection(section, random.NextRoundedDouble());
 
             // Call
-            void Call() => scenarioConfigurationPerFailureMechanismSection.A = a;
+            void Call() => scenarioConfigurationPerFailureMechanismSection.A = (RoundedDouble) a;
 
             // Assert
             const string expectedMessage = "De waarde voor 'a' moet in het bereik [0,0, 1,0] liggen.";
             TestHelper.AssertThrowsArgumentExceptionAndTestMessage<ArgumentOutOfRangeException>(Call, expectedMessage);
         }
-        
+
         [Test]
+        [TestCase(-0.0004)]
         [TestCase(0)]
         [TestCase(0.1)]
         [TestCase(1)]
+        [TestCase(1.0004)]
         [TestCase(0.0000001)]
         [TestCase(0.9999999)]
         public void A_ValidValue_SetsValue(double a)
         {
             // Setup
+            var random = new Random(21);
+
             FailureMechanismSection section = FailureMechanismSectionTestFactory.CreateFailureMechanismSection();
-            var scenarioConfigurationPerFailureMechanismSection = new ScenarioConfigurationPerFailureMechanismSection(section);
+            var scenarioConfigurationPerFailureMechanismSection = new TestScenarioConfigurationPerFailureMechanismSection(section, random.NextRoundedDouble());
 
             // Call
-            scenarioConfigurationPerFailureMechanismSection.A = a;
+            scenarioConfigurationPerFailureMechanismSection.A = (RoundedDouble) a;
 
             // Assert
-            Assert.AreEqual(a, scenarioConfigurationPerFailureMechanismSection.A);
+            Assert.AreEqual(3, scenarioConfigurationPerFailureMechanismSection.A.NumberOfDecimalPlaces);
+            Assert.AreEqual(a, scenarioConfigurationPerFailureMechanismSection.A, scenarioConfigurationPerFailureMechanismSection.A.GetAccuracy());
         }
+
+        private class TestScenarioConfigurationPerFailureMechanismSection : ScenarioConfigurationPerFailureMechanismSection
+        {
+            public TestScenarioConfigurationPerFailureMechanismSection(FailureMechanismSection section, RoundedDouble a) : base(section, a) {}
+        }
     }
 }
\ No newline at end of file
Index: Riskeer/Common/test/Riskeer.Common.Data.Test/Probability/ScenarioConfigurationPerFailureMechanismSectionExtensionsTest.cs
===================================================================
diff -u -r4001685fc423945628f49eb3064c4d23ec99df54 -rf46dff86a77c90d968fc00fc6e6306711ebf1b83
--- Riskeer/Common/test/Riskeer.Common.Data.Test/Probability/ScenarioConfigurationPerFailureMechanismSectionExtensionsTest.cs	(.../ScenarioConfigurationPerFailureMechanismSectionExtensionsTest.cs)	(revision 4001685fc423945628f49eb3064c4d23ec99df54)
+++ Riskeer/Common/test/Riskeer.Common.Data.Test/Probability/ScenarioConfigurationPerFailureMechanismSectionExtensionsTest.cs	(.../ScenarioConfigurationPerFailureMechanismSectionExtensionsTest.cs)	(revision f46dff86a77c90d968fc00fc6e6306711ebf1b83)
@@ -20,6 +20,7 @@
 // All rights reserved.
 
 using System;
+using Core.Common.Base.Data;
 using Core.Common.Base.Geometry;
 using NUnit.Framework;
 using Riskeer.Common.Data.FailureMechanism;
@@ -56,16 +57,18 @@
                 new Point2D(length, 0)
             });
 
-            var configuration = new ScenarioConfigurationPerFailureMechanismSection(section)
-            {
-                A = a
-            };
+            var configuration = new TestScenarioConfigurationPerFailureMechanismSection(section, (RoundedDouble) a);
 
             // Call
             double actualN = configuration.GetN(b);
 
             // Assert
             Assert.AreEqual(expectedN, actualN);
         }
+
+        private class TestScenarioConfigurationPerFailureMechanismSection : ScenarioConfigurationPerFailureMechanismSection
+        {
+            public TestScenarioConfigurationPerFailureMechanismSection(FailureMechanismSection section, RoundedDouble a) : base(section, a) {}
+        }
     }
 }
\ No newline at end of file