Index: Ringtoets/Common/src/Ringtoets.Common.Data/AssemblyTool/AssemblyCategoriesInputFactory.cs
===================================================================
diff -u
--- Ringtoets/Common/src/Ringtoets.Common.Data/AssemblyTool/AssemblyCategoriesInputFactory.cs	(revision 0)
+++ Ringtoets/Common/src/Ringtoets.Common.Data/AssemblyTool/AssemblyCategoriesInputFactory.cs	(revision 283def2fc4e1161789c176aa8f8e9e8bb4af3e4b)
@@ -0,0 +1,63 @@
+// Copyright (C) Stichting Deltares 2017. All rights reserved.
+//
+// This file is part of Ringtoets.
+//
+// Ringtoets 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 Ringtoets.AssemblyTool.Data;
+using Ringtoets.Common.Data.AssessmentSection;
+using Ringtoets.Common.Data.FailureMechanism;
+
+namespace Ringtoets.Common.Data.AssemblyTool
+{
+    /// <summary>
+    /// Factory for creating instances of <see cref="AssemblyCategoriesInput"/>.
+    /// </summary>
+    public static class AssemblyCategoriesInputFactory
+    {
+        /// <summary>
+        /// Creates an instance of <see cref="AssemblyCategoriesInput"/>.
+        /// </summary>
+        /// <param name="n">The 'N' parameter of the failure mechanism
+        /// used to factor in the 'length effect'.</param>
+        /// <param name="failureMechanism">The failure mechanism to create the input for.</param>
+        /// <param name="assessmentSection">The assessment section to create the input for.</param>
+        /// <returns>A <see cref="AssemblyCategoriesInput"/>.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when any parameter is <c>null</c>.</exception>
+        public static AssemblyCategoriesInput CreateAssemblyCategoriesInput(double n,
+                                                                            IFailureMechanism failureMechanism,
+                                                                            IAssessmentSection assessmentSection)
+        {
+            if (failureMechanism == null)
+            {
+                throw new ArgumentNullException(nameof(failureMechanism));
+            }
+
+            if (assessmentSection == null)
+            {
+                throw new ArgumentNullException(nameof(assessmentSection));
+            }
+
+            return new AssemblyCategoriesInput(n,
+                                               failureMechanism.Contribution,
+                                               assessmentSection.FailureMechanismContribution.SignalingNorm,
+                                               assessmentSection.FailureMechanismContribution.LowerLimitNorm);
+        }
+    }
+}
\ No newline at end of file
Index: Ringtoets/Common/test/Ringtoets.Common.Data.Test/AssemblyTool/AssemblyCategoriesInputFactoryTest.cs
===================================================================
diff -u
--- Ringtoets/Common/test/Ringtoets.Common.Data.Test/AssemblyTool/AssemblyCategoriesInputFactoryTest.cs	(revision 0)
+++ Ringtoets/Common/test/Ringtoets.Common.Data.Test/AssemblyTool/AssemblyCategoriesInputFactoryTest.cs	(revision 283def2fc4e1161789c176aa8f8e9e8bb4af3e4b)
@@ -0,0 +1,93 @@
+// Copyright (C) Stichting Deltares 2017. All rights reserved.
+//
+// This file is part of Ringtoets.
+//
+// Ringtoets 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 Ringtoets.AssemblyTool.Data;
+using Ringtoets.Common.Data.AssemblyTool;
+using Ringtoets.Common.Data.AssessmentSection;
+using Ringtoets.Common.Data.FailureMechanism;
+using Ringtoets.Common.Data.TestUtil;
+
+namespace Ringtoets.Common.Data.Test.AssemblyTool
+{
+    [TestFixture]
+    public class AssemblyCategoriesInputFactoryTest
+    {
+        [Test]
+        public void CreateAssemblyCategoriesInput_FailureMechanismNull_ThrowsArgumentNullException()
+        {
+            // Setup
+            var mocks = new MockRepository();
+            var assessmentSection = mocks.Stub<IAssessmentSection>();
+            mocks.ReplayAll();
+
+            // Call
+            TestDelegate test = () => AssemblyCategoriesInputFactory.CreateAssemblyCategoriesInput(new Random(39).NextDouble(),
+                                                                                                   null,
+                                                                                                   assessmentSection);
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(test);
+            Assert.AreEqual("failureMechanism", exception.ParamName);
+            mocks.VerifyAll();
+        }
+
+        [Test]
+        public void CreateAssemblyCategoriesInput_AssessmentSectionNull_ThrowsArgumentNullException()
+        {
+            // Setup
+            var mocks = new MockRepository();
+            var failureMechanism = mocks.Stub<IFailureMechanism>();
+            mocks.ReplayAll();
+
+            // Call
+            TestDelegate test = () => AssemblyCategoriesInputFactory.CreateAssemblyCategoriesInput(new Random(39).NextDouble(),
+                                                                                                   failureMechanism,
+                                                                                                   null);
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(test);
+            Assert.AreEqual("assessmentSection", exception.ParamName);
+            mocks.VerifyAll();
+        }
+
+        [Test]
+        public void CreateAssemblyCategoriesInput_WithValidInput_ReturnsExpectedAssemblyCategoriesInput()
+        {
+            // Setup
+            var random = new Random(39);
+            double n = random.NextDouble();
+            var failureMechanism = new TestFailureMechanism();
+            var assessmentSection = new AssessmentSectionStub();
+
+            // Call
+            AssemblyCategoriesInput assemblyCategoriesInput = AssemblyCategoriesInputFactory.CreateAssemblyCategoriesInput(n, failureMechanism, assessmentSection);
+
+            // Assert
+            Assert.AreEqual(n, assemblyCategoriesInput.N);
+            Assert.AreEqual(failureMechanism.Contribution / 100, assemblyCategoriesInput.FailureMechanismContribution);
+            Assert.AreEqual(assessmentSection.FailureMechanismContribution.SignalingNorm, assemblyCategoriesInput.SignalingNorm);
+            Assert.AreEqual(assessmentSection.FailureMechanismContribution.LowerLimitNorm, assemblyCategoriesInput.LowerLimitNorm);
+        }
+    }
+}
\ No newline at end of file