Index: dam engine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/Interfaces/IKernelWrapper.cs
===================================================================
diff -u -r675 -r686
--- dam engine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/Interfaces/IKernelWrapper.cs	(.../IKernelWrapper.cs)	(revision 675)
+++ dam engine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/Interfaces/IKernelWrapper.cs	(.../IKernelWrapper.cs)	(revision 686)
@@ -27,8 +27,11 @@
         /// </summary>
         /// <param name="damKernelInput">The dam kernel input.</param>
         /// <param name="kernelDataInput">The kernel data input.</param>
-        /// <returns>Result of the prepare</returns>
-        PrepareResult Prepare(DamKernelInput damKernelInput, out IKernelDataInput kernelDataInput);
+        /// <param name="kernelDataOutput">The kernel data output.</param>
+        /// <returns>
+        /// Result of the prepare
+        /// </returns>
+        PrepareResult Prepare(DamKernelInput damKernelInput, out IKernelDataInput kernelDataInput, out IKernelDataOutput kernelDataOutput);
         /// <summary>
         /// Validates the kernel data input.
         /// </summary>
@@ -40,9 +43,9 @@
         /// Performs a failure mechanism calcualtion based on the input.
         /// </summary>
         /// <param name="kernelDataInput">The kernel data input.</param>
+        /// <param name="kernelDataOutput">The kernel data output.</param>
         /// <param name="messages">The messages.</param>
-        /// <returns>Kernel output object</returns>
-        IKernelDataOutput Execute(IKernelDataInput kernelDataInput, out List<LogMessage> messages);
+        void Execute(IKernelDataInput kernelDataInput, IKernelDataOutput kernelDataOutput, out List<LogMessage> messages);
         /// <summary>
         /// Fills the dam result based on the kernel output.
         /// </summary>