Index: Riskeer/Integration/src/Riskeer.Integration.Forms/Factories/FailureMechanismAssemblyResultRowFactory.cs
===================================================================
diff -u
--- Riskeer/Integration/src/Riskeer.Integration.Forms/Factories/FailureMechanismAssemblyResultRowFactory.cs	(revision 0)
+++ Riskeer/Integration/src/Riskeer.Integration.Forms/Factories/FailureMechanismAssemblyResultRowFactory.cs	(revision 5f5ac7dfe21242c07f2f4bf9e2171e53c0e80122)
@@ -0,0 +1,84 @@
+// Copyright (C) Stichting Deltares 2021. All rights reserved.
+//
+// This file is part of Riskeer.
+//
+// Riskeer is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+//
+// All names, logos, and references to "Deltares" are registered trademarks of
+// Stichting Deltares and remain full property of Stichting Deltares at all times.
+// All rights reserved.
+
+using System;
+using Riskeer.Common.Data.Exceptions;
+using Riskeer.Common.Data.FailurePath;
+using Riskeer.Common.Forms.Helpers;
+using Riskeer.Integration.Forms.Views;
+
+namespace Riskeer.Integration.Forms.Factories
+{
+    /// <summary>
+    /// Factory to create instances of <see cref="FailureMechanismAssemblyResultRow"/>.
+    /// </summary>
+    internal static class FailureMechanismAssemblyResultRowFactory
+    {
+        /// <summary>
+        /// Creates a <see cref="FailureMechanismAssemblyResultRow"/> based on its input arguments.
+        /// </summary>
+        /// <param name="failureMechanism">The <see cref="IFailurePath"/> to create the row for.</param>
+        /// <param name="performAssemblyFunc">Performs the assembly for <paramref name="failureMechanism"/>.</param>
+        /// <returns>A <see cref="FailureMechanismAssemblyResultRow"/>.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when any parameter is <c>null</c>.</exception>
+        public static FailureMechanismAssemblyResultRow CreateRow(IFailurePath failureMechanism,
+                                                                  Func<double> performAssemblyFunc)
+        {
+            if (failureMechanism == null)
+            {
+                throw new ArgumentNullException(nameof(failureMechanism));
+            }
+
+            if (performAssemblyFunc == null)
+            {
+                throw new ArgumentNullException(nameof(performAssemblyFunc));
+            }
+
+            return failureMechanism.AssemblyResult.IsManualProbability()
+                       ? CreateManualAssemblyRow(failureMechanism)
+                       : CreateAutomaticAssemblyRow(failureMechanism, performAssemblyFunc);
+        }
+
+        private static FailureMechanismAssemblyResultRow CreateManualAssemblyRow(IFailurePath failureMechanism)
+        {
+            FailurePathAssemblyResult assemblyResult = failureMechanism.AssemblyResult;
+
+            string validationError = FailurePathAssemblyResultValidationHelper.GetValidationError(assemblyResult);
+            return !string.IsNullOrEmpty(validationError)
+                       ? new FailureMechanismAssemblyResultRow(failureMechanism, validationError)
+                       : new FailureMechanismAssemblyResultRow(failureMechanism, assemblyResult.ManualFailurePathAssemblyProbability);
+        }
+
+        private static FailureMechanismAssemblyResultRow CreateAutomaticAssemblyRow(IFailurePath failureMechanism,
+                                                                                    Func<double> performAssemblyFunc)
+        {
+            try
+            {
+                double assemblyResult = performAssemblyFunc();
+                return new FailureMechanismAssemblyResultRow(failureMechanism, assemblyResult);
+            }
+            catch (AssemblyException e)
+            {
+                return new FailureMechanismAssemblyResultRow(failureMechanism, e.Message);
+            }
+        }
+    }
+}
\ No newline at end of file
Index: Riskeer/Integration/test/Riskeer.Integration.Forms.Test/Factories/FailureMechanismAssemblyResultRowFactoryTest.cs
===================================================================
diff -u
--- Riskeer/Integration/test/Riskeer.Integration.Forms.Test/Factories/FailureMechanismAssemblyResultRowFactoryTest.cs	(revision 0)
+++ Riskeer/Integration/test/Riskeer.Integration.Forms.Test/Factories/FailureMechanismAssemblyResultRowFactoryTest.cs	(revision 5f5ac7dfe21242c07f2f4bf9e2171e53c0e80122)
@@ -0,0 +1,197 @@
+// Copyright (C) Stichting Deltares 2021. All rights reserved.
+//
+// This file is part of Riskeer.
+//
+// Riskeer is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+//
+// All names, logos, and references to "Deltares" are registered trademarks of
+// Stichting Deltares and remain full property of Stichting Deltares at all times.
+// All rights reserved.
+
+using System;
+using NUnit.Framework;
+using Rhino.Mocks;
+using Riskeer.Common.Data.Exceptions;
+using Riskeer.Common.Data.FailurePath;
+using Riskeer.Integration.Forms.Factories;
+using Riskeer.Integration.Forms.Views;
+
+namespace Riskeer.Integration.Forms.Test.Factories
+{
+    [TestFixture]
+    public class FailureMechanismAssemblyResultRowFactoryTest
+    {
+        private const int probabilityIndex = 2;
+
+        [Test]
+        public void CreateRow_FailureMechanismNull_ThrowsArgumentNullException()
+        {
+            // Call
+            void Call() => FailureMechanismAssemblyResultRowFactory.CreateRow(null, () => double.NaN);
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(Call);
+            Assert.AreEqual("failureMechanism", exception.ParamName);
+        }
+
+        [Test]
+        public void CreateRow_PerformAssemblyFuncNull_ThrowsArgumentNullException()
+        {
+            // Setup
+            var mocks = new MockRepository();
+            var failureMechanism = mocks.Stub<IFailurePath>();
+            mocks.ReplayAll();
+
+            // Call
+            void Call() => FailureMechanismAssemblyResultRowFactory.CreateRow(failureMechanism, null);
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(Call);
+            Assert.AreEqual("performAssemblyFunc", exception.ParamName);
+            mocks.VerifyAll();
+        }
+
+        [Test]
+        public void CreateRow_FailurePathWithPerformAssemblyFuncReturningResult_ReturnsExpectedRow()
+        {
+            // Setup
+            const string failureMechanismName = "Failure Mechanism Name";
+            const string failureMechanismCode = "Code";
+
+            var mocks = new MockRepository();
+            var failureMechanism = mocks.Stub<IFailurePath>();
+            failureMechanism.Stub(fm => fm.Name).Return(failureMechanismName);
+            failureMechanism.Stub(fm => fm.Code).Return(failureMechanismCode);
+            failureMechanism.Stub(fm => fm.AssemblyResult).Return(new FailurePathAssemblyResult
+            {
+                ProbabilityResultType = FailurePathAssemblyProbabilityResultType.Automatic
+            });
+            mocks.ReplayAll();
+
+            var random = new Random(21);
+            double assemblyResult = random.NextDouble();
+
+            // Call
+            FailureMechanismAssemblyResultRow row = FailureMechanismAssemblyResultRowFactory.CreateRow(failureMechanism, () => assemblyResult);
+
+            // Assert
+            Assert.IsEmpty(row.ColumnStateDefinitions[probabilityIndex].ErrorText);
+
+            Assert.AreEqual(failureMechanismName, row.Name);
+            Assert.AreEqual(failureMechanismCode, row.Code);
+            Assert.AreEqual(assemblyResult, row.Probability);
+
+            mocks.VerifyAll();
+        }
+
+        [Test]
+        public void CreateRow_FailurePathWithPerformAssemblyFuncThrowingAssemblyException_ReturnsExpectedRow()
+        {
+            // Setup
+            const string failureMechanismName = "Failure Mechanism Name";
+            const string failureMechanismCode = "Code";
+            const string errorMessage = "I am an error";
+
+            var mocks = new MockRepository();
+            var failureMechanism = mocks.Stub<IFailurePath>();
+            failureMechanism.Stub(fm => fm.Name).Return(failureMechanismName);
+            failureMechanism.Stub(fm => fm.Code).Return(failureMechanismCode);
+            failureMechanism.Stub(fm => fm.AssemblyResult).Return(new FailurePathAssemblyResult
+            {
+                ProbabilityResultType = FailurePathAssemblyProbabilityResultType.Automatic
+            });
+            mocks.ReplayAll();
+
+            // Call
+            FailureMechanismAssemblyResultRow row = FailureMechanismAssemblyResultRowFactory.CreateRow(
+                failureMechanism, () => throw new AssemblyException(errorMessage));
+
+            // Assert
+            Assert.AreEqual(errorMessage, row.ColumnStateDefinitions[probabilityIndex].ErrorText);
+
+            Assert.AreEqual(failureMechanismName, row.Name);
+            Assert.AreEqual(failureMechanismCode, row.Code);
+            Assert.IsNaN(row.Probability);
+
+            mocks.VerifyAll();
+        }
+
+        [Test]
+        public void CreateRow_FailurePathWithValidManualAssembly_ReturnsExpectedRow()
+        {
+            // Setup
+            const string failureMechanismName = "Failure Mechanism Name";
+            const string failureMechanismCode = "Code";
+
+            var random = new Random(21);
+            double assemblyResult = random.NextDouble();
+
+            var mocks = new MockRepository();
+            var failureMechanism = mocks.Stub<IFailurePath>();
+            failureMechanism.Stub(fm => fm.Name).Return(failureMechanismName);
+            failureMechanism.Stub(fm => fm.Code).Return(failureMechanismCode);
+            failureMechanism.Stub(fm => fm.AssemblyResult).Return(new FailurePathAssemblyResult
+            {
+                ManualFailurePathAssemblyProbability = assemblyResult,
+                ProbabilityResultType = FailurePathAssemblyProbabilityResultType.Manual
+            });
+            mocks.ReplayAll();
+
+            // Call
+            FailureMechanismAssemblyResultRow row = FailureMechanismAssemblyResultRowFactory.CreateRow(failureMechanism, () => double.NaN);
+
+            // Assert
+            Assert.IsEmpty(row.ColumnStateDefinitions[probabilityIndex].ErrorText);
+
+            Assert.AreEqual(failureMechanismName, row.Name);
+            Assert.AreEqual(failureMechanismCode, row.Code);
+            Assert.AreEqual(assemblyResult, row.Probability);
+
+            mocks.VerifyAll();
+        }
+
+        [Test]
+        public void CreateRow_FailurePathWithInvalidManualAssembly_ReturnsExpectedRow()
+        {
+            // Setup
+            const string failureMechanismName = "Failure Mechanism Name";
+            const string failureMechanismCode = "Code";
+
+            var mocks = new MockRepository();
+            var failureMechanism = mocks.Stub<IFailurePath>();
+            failureMechanism.Stub(fm => fm.Name).Return(failureMechanismName);
+            failureMechanism.Stub(fm => fm.Code).Return(failureMechanismCode);
+            failureMechanism.Stub(fm => fm.AssemblyResult).Return(new FailurePathAssemblyResult
+            {
+                ManualFailurePathAssemblyProbability = double.NaN,
+                ProbabilityResultType = FailurePathAssemblyProbabilityResultType.Manual
+            });
+            mocks.ReplayAll();
+
+            var random = new Random(21);
+
+            // Call
+            FailureMechanismAssemblyResultRow row = FailureMechanismAssemblyResultRowFactory.CreateRow(failureMechanism, () => random.NextDouble());
+
+            // Assert
+            Assert.AreEqual("Er moet een waarde worden ingevuld voor de faalkans.", row.ColumnStateDefinitions[probabilityIndex].ErrorText);
+
+            Assert.AreEqual(failureMechanismName, row.Name);
+            Assert.AreEqual(failureMechanismCode, row.Code);
+            Assert.IsNaN(row.Probability);
+
+            mocks.VerifyAll();
+        }
+    }
+}
\ No newline at end of file