FMS scheduling using backtracking-free heuristic search based on Petri net state equations

Abstract

This paper presents an efficient heuristic search method which does not require backtracking and is based on the state equations of Petri nets for scheduling flexible manufacturing systems (FMSs). If a heuristic method is precise and the model's terminal markings are the final markings (also there is no dead marking), it always leads to an optimal or near-optimal solution without backtracking. The approach proposed in this paper is based on a theory of Petri nets using net synthesis and state equations, such that these two conditions are satisfied. Moreover, backtracking-free means searching fewer states in the scheduling procedure, which corresponds to improving the scheduling efficiency.