PETRI NETS WITH K-SIMULTANEOUSLY ENABLED GENERALLY DISTRIBUTED TIMED TRANSITIONS

Stochastic Petri nets have been used to analyze the performance and re liability of complex systems comprising concurrency and synchronizatio n. Various extensions have been proposed in literature in order to bro aden their field of application to an increasingly larger range of rea l situations. In this paper we extend the class of Markov regenerative stochastic Petri nets (MRSPNs*), removing the restriction that at mo st one generally distributed timed transition can be enabled in ally m arking. This new class of Petri nets, which we call concurrent general ized Petri nets (CGPNs), allows simultaneous enabling of immediate, ex ponentially and generally distributed timed transitions, under the hyp othesis that the latter are all enabled at the same instant. The stoch astic process underlying a CGPN is shown to be still an MRGP. We evalu ate the kernel distribution of the underlying MRGP and define the step s required to generate it automatically. The methodology described is used to assess the behavior of a system in both steady-state and trans ient functioning conditions. (C) 1998 Elsevier Science B.V.