AN IMPROVED NUMERICAL ALGORITHM FOR CALCULATING STEADY-STATE SOLUTIONS OF DETERMINISTIC AND STOCHASTIC PETRI-NET MODELS

This paper introduces an efficient algorithm for calculating the time-dependent quantities required by the numerical solution process of Deterministic and Stochastic Petri Nets (DSPNs). The described method employs the randomization technique and a stable calculation of Poisson probabilities. A complete re-design and re-implementation of the appropriate components implemented in the version 1.4 of the software package GreatSPN has lead to significant savings in both computation time and memory space. These benefits are illustrated by DSPN models of an E(r)/D/1/K queueing system and a fault-tolerant clock synchronization system. These examples show that steady-state solutions of DSPNs are calculated with significantly less computational effort by the algorithm described in this paper than by the method implemented in the version 1.4 of the software package GreatSPN.