Index: Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Calculator/IDesignWaterLevelCalculator.cs
===================================================================
diff -u -r64d60335b1deab4bafd37f78f3514660cc4afb27 -r78815b3a2e147742759aedddf28c0ada6fb76152
--- Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Calculator/IDesignWaterLevelCalculator.cs	(.../IDesignWaterLevelCalculator.cs)	(revision 64d60335b1deab4bafd37f78f3514660cc4afb27)
+++ Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Calculator/IDesignWaterLevelCalculator.cs	(.../IDesignWaterLevelCalculator.cs)	(revision 78815b3a2e147742759aedddf28c0ada6fb76152)
@@ -21,12 +21,13 @@
 
 using Ringtoets.HydraRing.Calculation.Data.Input.Hydraulics;
 using Ringtoets.HydraRing.Calculation.Exceptions;
+using Ringtoets.HydraRing.Calculation.Parsers.IllustrationPoints;
 
 namespace Ringtoets.HydraRing.Calculation.Calculator
 {
     /// <summary>
-    /// Interface for a calculator which calculates the water level associated to the result of iterating towards a
-    /// probability of failure given a norm.
+    /// Interface for a calculator which calculates the water level associated to the result of 
+    /// iterating towards a probability of failure given a norm.
     /// </summary>
     public interface IDesignWaterLevelCalculator
     {
@@ -41,6 +42,11 @@
         double ReliabilityIndex { get; }
 
         /// <summary>
+        /// Gets the result of parsing the illustration points in the Hydra-Ring database.
+        /// </summary>
+        GeneralResult IllustrationPointsResult { get; }
+
+        /// <summary>
         /// Gets the value indicating whether the calculation converged.
         /// </summary>
         bool? Converged { get; }
@@ -64,6 +70,15 @@
         void Calculate(AssessmentLevelCalculationInput input);
 
         /// <summary>
+        /// Performs the actual calculation by running the Hydra-Ring executable.
+        /// Afterwards, sets the <see cref="IllustrationPointsResult"/>.
+        /// </summary>
+        /// <param name="input">The <see cref="AssessmentLevelCalculationInput"/> which contains all the necessary input
+        /// for the calculation.</param>
+        /// <exception cref="HydraRingCalculationException">Thrown when an error occurs while performing the calculation.</exception>
+        void CalculateWithIllustrationPoints(AssessmentLevelCalculationInput input);
+
+        /// <summary>
         /// Cancels any currently running Hydra-Ring calculation.
         /// </summary>
         void Cancel();