Design and development of a stochastic high-level Petri net system for FMS performance evaluation

The main thrust of this study was to develop and implement a Petri net model for performance evaluation of FMS in the early systems design stage. A utilization estimate of each machine is essential for this stage of system design. The main purpose was to develop a methodology for obtaining utilization rate of stations in FMS. In addition, bottleneck station, throughput rate and time in system were also points of interest. In this paper, Petri nets are used as a basic tool to evaluate the performance of an FMS. How to construct Petri nets automatically is a key issue for this investigation. Since high-level Petri nets provide the power of automatic construction of an entire Petri net from the description of the modelled system, it is adopted as the basis of the FMS performance evaluation system. The advantages of high-level Petri nets are presented. Examples are provided to illustrate the mechanism of the system.