diff --git a/src/eva2/tools/math/des/AbstractDESSolver.java b/src/eva2/tools/math/des/AbstractDESSolver.java
new file mode 100644
index 00000000..6beb6eb3
--- /dev/null
+++ b/src/eva2/tools/math/des/AbstractDESSolver.java
@@ -0,0 +1,16 @@
+/**
+ *
+ */
+package eva2.tools.math.des;
+
+/**
+ * This Class represents an RKSolver for event-driven DES
+ *
+ * @author Alexander Dörr
+ * @date 2010-02-04
+ *
+ */
+public abstract class AbstractDESSolver implements DESSolver {
+
+
+}
diff --git a/src/eva2/tools/math/des/EventDESystem.java b/src/eva2/tools/math/des/EventDESystem.java
new file mode 100644
index 00000000..5c310420
--- /dev/null
+++ b/src/eva2/tools/math/des/EventDESystem.java
@@ -0,0 +1,26 @@
+/**
+ *
+ */
+package eva2.tools.math.des;
+
+/**
+ * This Class represents an event-driven DES
+ *
+ * @author Alexander Dörr
+ * @date 2010-02-04
+ *
+ */
+public interface EventDESystem extends DESystem {
+
+ /**
+ * Returns an array with delays (entries >=0) for the
+ * events triggered either by the time t or by the concentrations
+ * of the species stored in Y. The new values for the species
+ * are stored in res. The positions in the array returned by this method
+ * correspond to the positions in Y/res.
+ *
+ * @return Returns an array with delays for the change of concentration due to events
+ */
+ public double[] processEvents(double t, double Y[], double res[]);
+
+}