Discretizing Time or States? A Comparative Study between DASSL and QSS

In this study, a system is presented and analyzed that automatically translates a model described within the Modelica framework into the Discrete Event System Specification (DEVS) formalism. More specifically, this work interfaces the open-source implementation of Modelica, OpenModelica, and one particular software tool for DEVS modeling and simulation, the PowerDEVS environment, which implements the Quantized State Systems (QSS) integration methods introduced by Kofman. The interface enables the automatic simulation of largescale models with both DASSL (using the OpenModelica run-time environment) and QSS (using PowerDEVS) and extracts features, such as accuracy and simulation time, that allow a quantitative comparison of these integration methods. In this way, meaningful insight can be obtained on their respective advantages and disadvantages when used for simulating real-world applications. Furthermore, the implemented interface allows any user without any knowledge of DEVS and/or QSS methods to simulate their systems in PowerDEVS by supplying a Modelica model as input only.