A Petri nets based object oriented tool for the scheduling of stochastic flexible manufacturing systems

Flexible manufacturing systems (FMS) have been taking a prominent place in production markets, but constant changes in production rates and product types force us to sort out constantly the scheduling problem that use to be NP-hard. Most commercial tools used to optimize FMS resources are analytical, and often limited to describing stationary relationships between FMS units. An object oriented simulation tool to prune the FMS Petri nets reachability tree is presented. This tool prunes the Petri net coverability tree using a heuristic algorithm, finding pseudo-optimal solutions for the FMS resource scheduling problem. The paper illustrates the usefulness of the tool to find a suitable batch size for a FMS example.