Index: Riskeer/Common/src/Riskeer.Common.Data/FailureMechanism/FailureMechanismSectionResult.cs
===================================================================
diff -u -r66b3865041fe3f402f54cd48c5aa9fe19179e627 -rd8e61e1c316db2f6f06f05f4911fd26ea072a0a1
--- Riskeer/Common/src/Riskeer.Common.Data/FailureMechanism/FailureMechanismSectionResult.cs	(.../FailureMechanismSectionResult.cs)	(revision 66b3865041fe3f402f54cd48c5aa9fe19179e627)
+++ Riskeer/Common/src/Riskeer.Common.Data/FailureMechanism/FailureMechanismSectionResult.cs	(.../FailureMechanismSectionResult.cs)	(revision d8e61e1c316db2f6f06f05f4911fd26ea072a0a1)
@@ -21,6 +21,8 @@
 
 using System;
 using Core.Common.Base;
+using Riskeer.Common.Data.Probability;
+using Riskeer.Common.Data.Properties;
 
 namespace Riskeer.Common.Data.FailureMechanism
 {
@@ -29,6 +31,8 @@
     /// </summary>
     public abstract class FailureMechanismSectionResult : Observable
     {
+        private double manualInitialFailureMechanismResultSectionProbability;
+
         /// <summary>
         /// Creates a new instance of <see cref="FailureMechanismSectionResult"/>.
         /// </summary>
@@ -44,6 +48,7 @@
             Section = section;
             IsRelevant = true;
             InitialFailureMechanismResult = InitialFailureMechanismResultType.Adopt;
+            ManualInitialFailureMechanismResultSectionProbability = double.NaN;
         }
 
         /// <summary>
@@ -60,5 +65,21 @@
         /// Gets or sets the initial failure mechanism result.
         /// </summary>
         public InitialFailureMechanismResultType InitialFailureMechanismResult { get; set; }
+
+        /// <summary>
+        /// Gets or sets the value of the manual initial failure mechanism result per failure mechanism section as a probability.
+        /// </summary>
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when <paramref name="value"/> is not in range [0,1].</exception>
+        public double ManualInitialFailureMechanismResultSectionProbability
+        {
+            get => manualInitialFailureMechanismResultSectionProbability;
+            set
+            {
+                ProbabilityHelper.ValidateProbability(value, null,
+                                                      Resources.ArbitraryProbabilityFailureMechanismSectionResult_AssessmentProbability_Value_needs_to_be_in_Range_0_,
+                                                      true);
+                manualInitialFailureMechanismResultSectionProbability = value;
+            }
+        }
     }
 }
\ No newline at end of file
Index: Riskeer/Common/test/Riskeer.Common.Data.Test/FailureMechanism/FailureMechanismSectionResultTest.cs
===================================================================
diff -u -r66b3865041fe3f402f54cd48c5aa9fe19179e627 -rd8e61e1c316db2f6f06f05f4911fd26ea072a0a1
--- Riskeer/Common/test/Riskeer.Common.Data.Test/FailureMechanism/FailureMechanismSectionResultTest.cs	(.../FailureMechanismSectionResultTest.cs)	(revision 66b3865041fe3f402f54cd48c5aa9fe19179e627)
+++ Riskeer/Common/test/Riskeer.Common.Data.Test/FailureMechanism/FailureMechanismSectionResultTest.cs	(.../FailureMechanismSectionResultTest.cs)	(revision d8e61e1c316db2f6f06f05f4911fd26ea072a0a1)
@@ -21,6 +21,7 @@
 
 using System;
 using Core.Common.Base;
+using Core.Common.TestUtil;
 using NUnit.Framework;
 using Riskeer.Common.Data.FailureMechanism;
 using Riskeer.Common.Data.TestUtil;
@@ -44,6 +45,7 @@
             Assert.AreSame(section, sectionResult.Section);
             Assert.IsTrue(sectionResult.IsRelevant);
             Assert.AreEqual(InitialFailureMechanismResultType.Adopt, sectionResult.InitialFailureMechanismResult);
+            Assert.IsNaN(sectionResult.ManualInitialFailureMechanismResultSectionProbability);
         }
 
         [Test]
@@ -56,7 +58,47 @@
             var exception = Assert.Throws<ArgumentNullException>(Call);
             Assert.AreEqual("section", exception.ParamName);
         }
+        
+        [Test]
+        [SetCulture("nl-NL")]
+        [TestCase(-20)]
+        [TestCase(-1e-6)]
+        [TestCase(1 + 1e-6)]
+        [TestCase(12)]
+        public void ManualInitialFailureMechanismResultSectionProbability_InvalidValue_ThrowsArgumentOutOfRangeException(double newValue)
+        {
+            // Setup
+            FailureMechanismSection section = FailureMechanismSectionTestFactory.CreateFailureMechanismSection();
+            var result = new TestFailureMechanismSectionResult(section);
 
+            // Call
+            void Call() => result.ManualInitialFailureMechanismResultSectionProbability = newValue;
+
+            // Assert
+            const string message = "De waarde voor de faalkans moet in het bereik [0,0, 1,0] liggen.";
+            TestHelper.AssertThrowsArgumentExceptionAndTestMessage<ArgumentOutOfRangeException>(Call, message);
+        }
+
+        [Test]
+        [TestCase(0)]
+        [TestCase(1e-6)]
+        [TestCase(0.5)]
+        [TestCase(1 - 1e-6)]
+        [TestCase(1)]
+        [TestCase(double.NaN)]
+        public void ManualInitialFailureMechanismResultSectionProbability_ValidValue_NewValueSet(double newValue)
+        {
+            // Setup
+            FailureMechanismSection section = FailureMechanismSectionTestFactory.CreateFailureMechanismSection();
+            var result = new TestFailureMechanismSectionResult(section);
+
+            // Call
+            result.ManualInitialFailureMechanismResultSectionProbability = newValue;
+
+            // Assert
+            Assert.AreEqual(newValue, result.ManualInitialFailureMechanismResultSectionProbability);
+        }
+
         private class TestFailureMechanismSectionResult : FailureMechanismSectionResult
         {
             public TestFailureMechanismSectionResult(FailureMechanismSection section) : base(section) {}
Index: Riskeer/Piping/src/Riskeer.Piping.Data/PipingFailureMechanismSectionResult.cs
===================================================================
diff -u -r896749236261cd0956021990f904a353362f6bd5 -rd8e61e1c316db2f6f06f05f4911fd26ea072a0a1
--- Riskeer/Piping/src/Riskeer.Piping.Data/PipingFailureMechanismSectionResult.cs	(.../PipingFailureMechanismSectionResult.cs)	(revision 896749236261cd0956021990f904a353362f6bd5)
+++ Riskeer/Piping/src/Riskeer.Piping.Data/PipingFailureMechanismSectionResult.cs	(.../PipingFailureMechanismSectionResult.cs)	(revision d8e61e1c316db2f6f06f05f4911fd26ea072a0a1)
@@ -19,7 +19,10 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
+using System;
 using Riskeer.Common.Data.FailureMechanism;
+using Riskeer.Common.Data.Probability;
+using RiskeerCommonDataResources = Riskeer.Common.Data.Properties.Resources;
 
 namespace Riskeer.Piping.Data
 {
@@ -29,11 +32,32 @@
     /// </summary>
     public class PipingFailureMechanismSectionResult : FailureMechanismSectionResult
     {
+        private double manualInitialFailureMechanismResultProfileProbability;
+
         /// <inheritdoc />
         /// <summary>
         /// Creates a new instance of <see cref="PipingFailureMechanismSectionResult"/>.
         /// </summary>
         public PipingFailureMechanismSectionResult(FailureMechanismSection section)
-            : base(section) {}
+            : base(section)
+        {
+            ManualInitialFailureMechanismResultProfileProbability = double.NaN;
+        }
+        
+        /// <summary>
+        /// Gets or sets the value of the manual initial failure mechanism result per profile as a probability.
+        /// </summary>
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when <paramref name="value"/> is not in range [0,1].</exception>
+        public double ManualInitialFailureMechanismResultProfileProbability
+        {
+            get => manualInitialFailureMechanismResultProfileProbability;
+            set
+            {
+                ProbabilityHelper.ValidateProbability(value, null,
+                                                      RiskeerCommonDataResources.ArbitraryProbabilityFailureMechanismSectionResult_AssessmentProbability_Value_needs_to_be_in_Range_0_,
+                                                      true);
+                manualInitialFailureMechanismResultProfileProbability = value;
+            }
+        }
     }
 }
\ No newline at end of file
Index: Riskeer/Piping/test/Riskeer.Piping.Data.Test/PipingFailureMechanismSectionResultTest.cs
===================================================================
diff -u -r896749236261cd0956021990f904a353362f6bd5 -rd8e61e1c316db2f6f06f05f4911fd26ea072a0a1
--- Riskeer/Piping/test/Riskeer.Piping.Data.Test/PipingFailureMechanismSectionResultTest.cs	(.../PipingFailureMechanismSectionResultTest.cs)	(revision 896749236261cd0956021990f904a353362f6bd5)
+++ Riskeer/Piping/test/Riskeer.Piping.Data.Test/PipingFailureMechanismSectionResultTest.cs	(.../PipingFailureMechanismSectionResultTest.cs)	(revision d8e61e1c316db2f6f06f05f4911fd26ea072a0a1)
@@ -19,6 +19,8 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
+using System;
+using Core.Common.TestUtil;
 using NUnit.Framework;
 using Riskeer.Common.Data.FailureMechanism;
 using Riskeer.Common.Data.TestUtil;
@@ -36,6 +38,47 @@
 
             // Assert
             Assert.IsInstanceOf<FailureMechanismSectionResult>(sectionResult);
+            Assert.IsNaN(sectionResult.ManualInitialFailureMechanismResultProfileProbability);
         }
+
+        [Test]
+        [SetCulture("nl-NL")]
+        [TestCase(-20)]
+        [TestCase(-1e-6)]
+        [TestCase(1 + 1e-6)]
+        [TestCase(12)]
+        public void ManualInitialFailureMechanismResultProfileProbability_InvalidValue_ThrowsArgumentOutOfRangeException(double newValue)
+        {
+            // Setup
+            FailureMechanismSection section = FailureMechanismSectionTestFactory.CreateFailureMechanismSection();
+            var result = new PipingFailureMechanismSectionResult(section);
+
+            // Call
+            void Call() => result.ManualInitialFailureMechanismResultProfileProbability = newValue;
+
+            // Assert
+            const string message = "De waarde voor de faalkans moet in het bereik [0,0, 1,0] liggen.";
+            TestHelper.AssertThrowsArgumentExceptionAndTestMessage<ArgumentOutOfRangeException>(Call, message);
+        }
+
+        [Test]
+        [TestCase(0)]
+        [TestCase(1e-6)]
+        [TestCase(0.5)]
+        [TestCase(1 - 1e-6)]
+        [TestCase(1)]
+        [TestCase(double.NaN)]
+        public void ManualInitialFailureMechanismResultProfileProbability_ValidValue_NewValueSet(double newValue)
+        {
+            // Setup
+            FailureMechanismSection section = FailureMechanismSectionTestFactory.CreateFailureMechanismSection();
+            var result = new PipingFailureMechanismSectionResult(section);
+
+            // Call
+            result.ManualInitialFailureMechanismResultProfileProbability = newValue;
+
+            // Assert
+            Assert.AreEqual(newValue, result.ManualInitialFailureMechanismResultProfileProbability);
+        }
     }
 }
\ No newline at end of file