Abstract

To utilize the PDEVS formalism for the practical modeling and simulation of discrete-event systems, the recently proposed variant NSA-DEVS combines the Mealy behaviour of RPDEVS with a simple simulator algorithm by employing infinitesimal time delays. To further test the practical usefulness of this new approach, four simple systems showing non-trivial event-cascades are modeled and simulated within a concrete NSA-DEVS environment: A comparator-switch model, a digital circuit with flip-flops, a basic queue-server system and a more complex queuing system. Their simple implementations show that the potentially large number of delay parameters in NSA-DEVS in practice reduces to a single default value, which only occasionally has to be tuned to adapt to complex causal behaviour. In addition, by providing precise formal definitions of the models and by looking closely at the behaviour of the abstract simulator, the validity of the NSA-DEVS formalism is further substantiated.