Stochastic modeling using DSPNexpress

This article outlines a graphical software package for performance and dependability modeling with deterministic and stochastic Petri nets (DSPNs). The package is called DSPNexpress because its main scientific contribution lies in its efficient numerical solution component. The development of DSPNexpress has been motivated by the lack of a software package for an efficient numerical analysis of Deterministic and stochastic Petri nets (DSPNs) and the complexity requirements imposed by evaluating design alternatives for hardware and software components of multicomputer systems. The main scientific contribution of DSPNexpress lies in its efficient numerical solution component. The version 1.3 of DSPNexpress solves complex DSPNs with four orders of magnitude less CPU time than the previously known numerical method. As a consequence, DSPNexpress is able to calculate steady-state solutions of complex DSPNs with reasonable computational effort on a modern workstation (e.g. a DSPN with 100000 tangible marking and 5000000 state transitions with mild stiffness can be solved in 1 hour of CPU time on a Sun Spare station 2). The article summarizes the main innovative features of the software package DSPNexpress.