Index: Ringtoets/AssemblyTool/src/Ringtoets.AssemblyTool.Data/CombinedFailureMechanismSectionAssembly.cs
===================================================================
diff -u -r9537a33b0502e46af43b6e1372b87984fe7f2a88 -r6b7fc9d682090343904b25d6c3ecb10b0166decf
--- Ringtoets/AssemblyTool/src/Ringtoets.AssemblyTool.Data/CombinedFailureMechanismSectionAssembly.cs	(.../CombinedFailureMechanismSectionAssembly.cs)	(revision 9537a33b0502e46af43b6e1372b87984fe7f2a88)
+++ Ringtoets/AssemblyTool/src/Ringtoets.AssemblyTool.Data/CombinedFailureMechanismSectionAssembly.cs	(.../CombinedFailureMechanismSectionAssembly.cs)	(revision 6b7fc9d682090343904b25d6c3ecb10b0166decf)
@@ -32,45 +32,32 @@
         /// <summary>
         /// Creates a new instance of <see cref="CombinedFailureMechanismSectionAssembly"/>.
         /// </summary>
-        /// <param name="sectionStart">The start of the section from the beginning of the reference line.</param>
-        /// <param name="sectionEnd">The end of the section from the beginning of the reference line.</param>
-        /// <param name="combinedResult">The combined assembly result.</param>
+        /// <param name="section">The section of the assembly.</param>
         /// <param name="failureMechanismResults">The assembly results per failure mechanism.</param>
-        /// <exception cref="ArgumentNullException">Thrown when <paramref name="failureMechanismResults"/>
-        /// is <c>null</c>.</exception>
-        public CombinedFailureMechanismSectionAssembly(double sectionStart, double sectionEnd,
-                                                       FailureMechanismSectionAssemblyCategoryGroup combinedResult,
+        /// <exception cref="ArgumentNullException">Thrown when any parameter is <c>null</c>.</exception>
+        public CombinedFailureMechanismSectionAssembly(CombinedAssemblyFailureMechanismSection section,
                                                        IEnumerable<FailureMechanismSectionAssemblyCategoryGroup> failureMechanismResults)
         {
+            if (section == null)
+            {
+                throw new ArgumentNullException(nameof(section));
+            }
+
             if (failureMechanismResults == null)
             {
                 throw new ArgumentNullException(nameof(failureMechanismResults));
             }
 
-            SectionStart = sectionStart;
-            SectionEnd = sectionEnd;
-            CombinedResult = combinedResult;
+            Section = section;
             FailureMechanismResults = failureMechanismResults;
         }
-
+        
         /// <summary>
-        /// Gets the start of the section from the beginning of the reference line.
-        /// [m]
+        /// Gets the section of the assembly.
         /// </summary>
-        public double SectionStart { get; }
+        public CombinedAssemblyFailureMechanismSection Section { get; }
 
         /// <summary>
-        /// Gets the end of the section from the beginning of the reference line.
-        /// [m]
-        /// </summary>
-        public double SectionEnd { get; }
-
-        /// <summary>
-        /// Gets the combined assembly result.
-        /// </summary>
-        public FailureMechanismSectionAssemblyCategoryGroup CombinedResult { get; }
-
-        /// <summary>
         /// Gets the assembly results per failure mechanism.
         /// </summary>
         public IEnumerable<FailureMechanismSectionAssemblyCategoryGroup> FailureMechanismResults { get; }
Index: Ringtoets/AssemblyTool/src/Ringtoets.AssemblyTool.KernelWrapper/Creators/CombinedFailureMechanismSectionAssemblyCreator.cs
===================================================================
diff -u -r6d88e6a0ed8c51eaf54bc6facfd1b0a9a6d1aafe -r6b7fc9d682090343904b25d6c3ecb10b0166decf
--- Ringtoets/AssemblyTool/src/Ringtoets.AssemblyTool.KernelWrapper/Creators/CombinedFailureMechanismSectionAssemblyCreator.cs	(.../CombinedFailureMechanismSectionAssemblyCreator.cs)	(revision 6d88e6a0ed8c51eaf54bc6facfd1b0a9a6d1aafe)
+++ Ringtoets/AssemblyTool/src/Ringtoets.AssemblyTool.KernelWrapper/Creators/CombinedFailureMechanismSectionAssemblyCreator.cs	(.../CombinedFailureMechanismSectionAssemblyCreator.cs)	(revision 6b7fc9d682090343904b25d6c3ecb10b0166decf)
@@ -54,8 +54,7 @@
             {
                 FmSectionWithDirectCategory section = result.CombinedSectionResult.ElementAt(i);
                 sectionAssemblies.Add(new CombinedFailureMechanismSectionAssembly(
-                                          section.SectionStart, section.SectionEnd,
-                                          FailureMechanismSectionAssemblyCreator.CreateFailureMechanismSectionAssemblyCategoryGroup(section.Category),
+                                          CreateSection(section),
                                           result.ResultPerFailureMechanism
                                                 .Select(failureMechanismSectionList =>
                                                             (FmSectionWithDirectCategory) failureMechanismSectionList.Results.ElementAt(i))
@@ -66,5 +65,12 @@
 
             return sectionAssemblies;
         }
+
+        private static CombinedAssemblyFailureMechanismSection CreateSection(FmSectionWithDirectCategory section)
+        {
+            return new CombinedAssemblyFailureMechanismSection(
+                section.SectionStart, section.SectionEnd,
+                FailureMechanismSectionAssemblyCreator.CreateFailureMechanismSectionAssemblyCategoryGroup(section.Category));
+        }
     }
 }
\ No newline at end of file
Index: Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.Data.Test/CombinedFailureMechanismSectionAssemblyTest.cs
===================================================================
diff -u -r9537a33b0502e46af43b6e1372b87984fe7f2a88 -r6b7fc9d682090343904b25d6c3ecb10b0166decf
--- Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.Data.Test/CombinedFailureMechanismSectionAssemblyTest.cs	(.../CombinedFailureMechanismSectionAssemblyTest.cs)	(revision 9537a33b0502e46af43b6e1372b87984fe7f2a88)
+++ Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.Data.Test/CombinedFailureMechanismSectionAssemblyTest.cs	(.../CombinedFailureMechanismSectionAssemblyTest.cs)	(revision 6b7fc9d682090343904b25d6c3ecb10b0166decf)
@@ -31,15 +31,26 @@
     public class CombinedFailureMechanismSectionAssemblyTest
     {
         [Test]
+        public void Constructor_SectionNull_ThrowsArgumentNullException()
+        {
+            // Call
+            TestDelegate call = () => new CombinedFailureMechanismSectionAssembly(null, Enumerable.Empty<FailureMechanismSectionAssemblyCategoryGroup>());
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(call);
+            Assert.AreEqual("section", exception.ParamName);
+        }
+
+        [Test]
         public void Constructor_FailureMechanismResultsNull_ThrowsArgumentNullException()
         {
             // Setup
             var random = new Random(21);
+            var section = new CombinedAssemblyFailureMechanismSection(random.NextDouble(), random.NextDouble(),
+                                                                      random.NextEnumValue<FailureMechanismSectionAssemblyCategoryGroup>());
 
             // Call
-            TestDelegate call = () => new CombinedFailureMechanismSectionAssembly(random.NextDouble(), random.NextDouble(),
-                                                                                  random.NextEnumValue<FailureMechanismSectionAssemblyCategoryGroup>(),
-                                                                                  null);
+            TestDelegate call = () => new CombinedFailureMechanismSectionAssembly(section, null);
 
             // Assert
             var exception = Assert.Throws<ArgumentNullException>(call);
@@ -51,18 +62,15 @@
         {
             // Setup
             var random = new Random(21);
-            double sectionStart = random.NextDouble();
-            double sectionEnd = random.NextDouble();
-            var combinedResult = random.NextEnumValue<FailureMechanismSectionAssemblyCategoryGroup>();
+            var section = new CombinedAssemblyFailureMechanismSection(random.NextDouble(), random.NextDouble(),
+                                                                      random.NextEnumValue<FailureMechanismSectionAssemblyCategoryGroup>());
             IEnumerable<FailureMechanismSectionAssemblyCategoryGroup> failureMechanismResults = Enumerable.Empty<FailureMechanismSectionAssemblyCategoryGroup>();
 
             // Call
-            var assembly = new CombinedFailureMechanismSectionAssembly(sectionStart, sectionEnd, combinedResult, failureMechanismResults);
+            var assembly = new CombinedFailureMechanismSectionAssembly(section, failureMechanismResults);
 
             // Assert
-            Assert.AreEqual(sectionStart, assembly.SectionStart);
-            Assert.AreEqual(sectionEnd, assembly.SectionEnd);
-            Assert.AreEqual(combinedResult, assembly.CombinedResult);
+            Assert.AreSame(section, assembly.Section);
             Assert.AreSame(failureMechanismResults, assembly.FailureMechanismResults);
         }
     }
Index: Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.Test/Creators/CombinedFailureMechanismSectionAssemblyCreatorTest.cs
===================================================================
diff -u -r6d88e6a0ed8c51eaf54bc6facfd1b0a9a6d1aafe -r6b7fc9d682090343904b25d6c3ecb10b0166decf
--- Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.Test/Creators/CombinedFailureMechanismSectionAssemblyCreatorTest.cs	(.../CombinedFailureMechanismSectionAssemblyCreatorTest.cs)	(revision 6d88e6a0ed8c51eaf54bc6facfd1b0a9a6d1aafe)
+++ Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.Test/Creators/CombinedFailureMechanismSectionAssemblyCreatorTest.cs	(.../CombinedFailureMechanismSectionAssemblyCreatorTest.cs)	(revision 6b7fc9d682090343904b25d6c3ecb10b0166decf)
@@ -92,9 +92,9 @@
             Assert.AreEqual(3, results.Length);
             for (var i = 0; i < results.Length; i++)
             {
-                Assert.AreEqual(sections[i].Item1, results[i].SectionStart);
-                Assert.AreEqual(sections[i].Item2, results[i].SectionEnd);
-                Assert.AreEqual(GetResultGroup(combinedResults[i].Category), results[i].CombinedResult);
+                Assert.AreEqual(sections[i].Item1, results[i].Section.SectionStart);
+                Assert.AreEqual(sections[i].Item2, results[i].Section.SectionEnd);
+                Assert.AreEqual(GetResultGroup(combinedResults[i].Category), results[i].Section.CategoryGroup);
                 Assert.AreEqual(failureMechanismResults.Length, results[i].FailureMechanismResults.Count());
 
                 for (var j = 0; j < failureMechanismResults.Length; j++)
Index: Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil.Test/Calculators/Assembly/AssessmentSectionAssemblyCalculatorStubTest.cs
===================================================================
diff -u -rb3a784920b0a48ad0504049e4e9f6f663082b616 -r6b7fc9d682090343904b25d6c3ecb10b0166decf
--- Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil.Test/Calculators/Assembly/AssessmentSectionAssemblyCalculatorStubTest.cs	(.../AssessmentSectionAssemblyCalculatorStubTest.cs)	(revision b3a784920b0a48ad0504049e4e9f6f663082b616)
+++ Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil.Test/Calculators/Assembly/AssessmentSectionAssemblyCalculatorStubTest.cs	(.../AssessmentSectionAssemblyCalculatorStubTest.cs)	(revision 6b7fc9d682090343904b25d6c3ecb10b0166decf)
@@ -279,14 +279,16 @@
             // Assert
             var expectedOutput = new[]
             {
-                new CombinedFailureMechanismSectionAssembly(0, 1, FailureMechanismSectionAssemblyCategoryGroup.IIIv, new[]
-                {
-                    FailureMechanismSectionAssemblyCategoryGroup.VIv
-                }),
+                new CombinedFailureMechanismSectionAssembly(
+                    new CombinedAssemblyFailureMechanismSection(0, 1, FailureMechanismSectionAssemblyCategoryGroup.IIIv)
+                    , new[]
+                    {
+                        FailureMechanismSectionAssemblyCategoryGroup.VIv
+                    })
             };
-            Assert.AreEqual(expectedOutput[0].SectionStart, output[0].SectionStart);
-            Assert.AreEqual(expectedOutput[0].SectionEnd, output[0].SectionEnd);
-            Assert.AreEqual(expectedOutput[0].CombinedResult, output[0].CombinedResult);
+            Assert.AreEqual(expectedOutput[0].Section.SectionStart, output[0].Section.SectionStart);
+            Assert.AreEqual(expectedOutput[0].Section.SectionEnd, output[0].Section.SectionEnd);
+            Assert.AreEqual(expectedOutput[0].Section.CategoryGroup, output[0].Section.CategoryGroup);
             CollectionAssert.AreEqual(expectedOutput[0].FailureMechanismResults, output[0].FailureMechanismResults);
         }
 
@@ -300,7 +302,8 @@
                 CombinedFailureMechanismSectionAssemblyOutput = new[]
                 {
                     new CombinedFailureMechanismSectionAssembly(
-                        random.NextDouble(), random.NextDouble(), random.NextEnumValue<FailureMechanismSectionAssemblyCategoryGroup>(),
+                        new CombinedAssemblyFailureMechanismSection(random.NextDouble(), random.NextDouble(),
+                                                                    random.NextEnumValue<FailureMechanismSectionAssemblyCategoryGroup>()),
                         new[]
                         {
                             random.NextEnumValue<FailureMechanismSectionAssemblyCategoryGroup>()
Index: Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil/Calculators/Assembly/AssessmentSectionAssemblyCalculatorStub.cs
===================================================================
diff -u -rb3a784920b0a48ad0504049e4e9f6f663082b616 -r6b7fc9d682090343904b25d6c3ecb10b0166decf
--- Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil/Calculators/Assembly/AssessmentSectionAssemblyCalculatorStub.cs	(.../AssessmentSectionAssemblyCalculatorStub.cs)	(revision b3a784920b0a48ad0504049e4e9f6f663082b616)
+++ Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil/Calculators/Assembly/AssessmentSectionAssemblyCalculatorStub.cs	(.../AssessmentSectionAssemblyCalculatorStub.cs)	(revision 6b7fc9d682090343904b25d6c3ecb10b0166decf)
@@ -162,10 +162,12 @@
 
             return CombinedFailureMechanismSectionAssemblyOutput ?? (CombinedFailureMechanismSectionAssemblyOutput = new[]
             {
-                new CombinedFailureMechanismSectionAssembly(0, 1, FailureMechanismSectionAssemblyCategoryGroup.IIIv, new[]
-                {
-                    FailureMechanismSectionAssemblyCategoryGroup.VIv
-                }),
+                new CombinedFailureMechanismSectionAssembly(
+                    new CombinedAssemblyFailureMechanismSection(0, 1, FailureMechanismSectionAssemblyCategoryGroup.IIIv),
+                    new[]
+                    {
+                        FailureMechanismSectionAssemblyCategoryGroup.VIv
+                    })
             });
         }
     }