In: Proc. 4th Int. Workshop on Petri Nets and Performance Models (PNPM'91), Melbourne, Australia, pages 300-309. IEEE Comp. Soc. Press, December 1991.
Abstract: In this paper we address the problem of calculating performability measures from performability models of fault-tolerant computer systems. Since these systems tend to be large and complex, the corresponding performability models will in general also be large and complex. To alleviate the largeness problem to some extent we use generalized stochastic Petri nets to describe the models. Still however, many models can not be solved with the current numerical techniques, although they are conveniently and often compactly described. In this paper we discuss two heuristic state space truncation techniques that allow us to obtain very good approximations while only assessing a few percent of the overall state space. We give examples of the usage, but also theoretical evidence in the correctness of the employed truncation techniques. We furthermore show that GSPNs are very suitable for implementing (describing) the proposed truncation techniques. We finally address related work.