Index: Core/Common/test/Core.Common.TestUtil.Test/TestHelperTest.cs
===================================================================
diff -u -rad66b6e2df465acc900aa792c99dfdacee3f3a32 -rac16d6c29bbb756651b4f8a25e58fd9b5e0f9c67
--- Core/Common/test/Core.Common.TestUtil.Test/TestHelperTest.cs	(.../TestHelperTest.cs)	(revision ad66b6e2df465acc900aa792c99dfdacee3f3a32)
+++ Core/Common/test/Core.Common.TestUtil.Test/TestHelperTest.cs	(.../TestHelperTest.cs)	(revision ac16d6c29bbb756651b4f8a25e58fd9b5e0f9c67)
@@ -250,7 +250,7 @@
 
             path = TestHelper.GetTestDataPath(TestDataPath.Ringtoets.Piping.IO);
             Assert.IsTrue(Directory.Exists(path));
-            
+
             path = TestHelper.GetTestDataPath(TestDataPath.Ringtoets.Revetment.IO);
             Assert.IsTrue(Directory.Exists(path));
         }
@@ -1153,6 +1153,24 @@
             Assert.Throws<AssertionException>(test);
         }
 
+        [Test]
+        public void PerformActionWithDelayedAssert_WithAllData_DoesNotThrow()
+        {
+            // Setup
+            var callPerformed = false;
+            var assertPerformed = false;
+            var callAction = new Action(() => callPerformed = true);
+            var assertAction = new Action(() => assertPerformed = true);
+            const int delay = 10;
+
+            // Call
+            TestHelper.PerformActionWithDelayedAssert(callAction, assertAction, delay);
+
+            // Assert
+            Assert.IsTrue(callPerformed);
+            Assert.IsTrue(assertPerformed);
+        }
+
         private class TestEqualSameObject
         {
             private readonly int someInt;
@@ -1168,14 +1186,17 @@
                 {
                     return false;
                 }
+
                 if (ReferenceEquals(this, obj))
                 {
                     return true;
                 }
+
                 if (obj.GetType() != GetType())
                 {
                     return false;
                 }
+
                 return Equals((TestEqualSameObject) obj);
             }
 
Index: Core/Common/test/Core.Common.TestUtil/TestHelper.cs
===================================================================
diff -u -rfb6ca0c708e591684db8b4e877ec4c38b094b5c9 -rac16d6c29bbb756651b4f8a25e58fd9b5e0f9c67
--- Core/Common/test/Core.Common.TestUtil/TestHelper.cs	(.../TestHelper.cs)	(revision fb6ca0c708e591684db8b4e877ec4c38b094b5c9)
+++ Core/Common/test/Core.Common.TestUtil/TestHelper.cs	(.../TestHelper.cs)	(revision ac16d6c29bbb756651b4f8a25e58fd9b5e0f9c67)
@@ -35,6 +35,7 @@
 using log4net.Core;
 using NUnit.Framework;
 using NUnit.Framework.Internal;
+using Timer = System.Timers.Timer;
 
 namespace Core.Common.TestUtil
 {
@@ -66,6 +67,7 @@
             {
                 Directory.CreateDirectory(scratchPadPath);
             }
+
             return scratchPadPath;
         }
 
@@ -113,6 +115,7 @@
             try
             {
                 using (File.OpenWrite(pathToFile)) {}
+
                 return true;
             }
             catch (IOException)
@@ -269,6 +272,7 @@
                 Assert.IsNull(actualImage);
                 return;
             }
+
             Assert.IsNotNull(actualImage);
 
             Assert.AreEqual(expectedImage.Size, actualImage.Size);
@@ -337,6 +341,7 @@
 
                 message = string.Join(Environment.NewLine, customMessageParts.ToArray());
             }
+
             Assert.AreEqual(expectedCustomMessage, message);
             return exception;
         }
@@ -470,6 +475,7 @@
                     Assert.AreSame(expectedEnumerator.Current, actualEnumerator.Current);
                 }
             }
+
             Assert.IsFalse(actualEnumerator.MoveNext());
         }
 
@@ -497,6 +503,7 @@
                     Assert.AreNotSame(expectedEnumerator.Current, actualEnumerator.Current);
                 }
             }
+
             Assert.IsFalse(actualEnumerator.MoveNext());
         }
 
@@ -531,11 +538,39 @@
                         Assert.IsTrue(equalityComparer.Equals(expectedEnumerator.Current, actualEnumerator.Current));
                     }
                 }
+
                 Assert.IsFalse(actualEnumerator.MoveNext());
             }
         }
 
         /// <summary>
+        /// Performs the call and asserts after the delay has passed.
+        /// </summary>
+        /// <param name="callAction">The call to perform.</param>
+        /// <param name="assertAction">The assert to perform.</param>
+        /// <param name="delay">The delay by which the assert action is performed
+        /// after the call action is done.</param>
+        /// <exception cref="AssertionException">Thrown when an assert in the
+        /// <paramref name="assertAction"/> failed.</exception>
+        public static void PerformActionWithDelayedAssert(Action callAction, Action assertAction, int delay)
+        {
+            var timer = new Timer
+            {
+                Interval = delay
+            };
+
+            var timerEnded = false;
+            timer.Elapsed += (sender, args) => { timerEnded = true; };
+
+            callAction();
+            timer.Start();
+
+            while (!timerEnded) {}
+
+            assertAction();
+        }
+
+        /// <summary>
         /// Determines whether a class is decorated with a <see cref="TypeConverterAttribute"/>
         /// of a given type.
         /// </summary>
@@ -705,6 +740,7 @@
                     imageColors[index++] = bitmap.GetPixel(j, i);
                 }
             }
+
             return imageColors;
         }
     }