In: Journal of Parallel and Distributed Computing 15, pages 225-237. 1992.
Abstract: A new class of nets, called S-nets, is introduced for the performance analysis of scheduling algorithms used in real-time systems. Deterministic timed Petri nets do not adequately model the scheduling of resources encountered in real-time systems, and need to be augmented with resource places and signal places, and a scheduler block, to facilitate the modeling of scheduling algorithms. The tokens are colored, and the transition firing rules are suitably modified. Further, the concept of transitionfolding is used, to get intuitively, simple models of multiframe real-time systems. Two generic performance measures, called ``loadindex'' and ``balance index'', which characterize the resource utilization and the uniformity of workload distribution, respectively, are defined. The utility of S-nets for evaluating heuristic-based scheduling schemes is illustrated by considering three heuristics for realtime scheduling.