In: Proc. 9th IFAC Symp. on Information Control in Manufacturing (INCOM'98), 24-26 June 1998, Nancy-Metz, France, Vol. 2, pages 429-434. 1998.
Abstract: A heuristic search approach for scheduling two classes of flexible manufacturing systems (FMSs) that contain assembly operations is proposed. The FMSs are modeled by two classes of Petri nets, called generalized symmetric and asymmetric nets. The problem of minimizing makespan is transformed into searching the reachability graph for the optimal (minimal time) firing sequence from the initial marking (state) to the goal marking. A solution of the state equation constitutes a part of the heuristic function. The dynamic information of the nets, such as concurrency and synchronization, is used to adjust the heuristic function since the solution of the state equation may over-estimate the real cost. Simulation results for tuning the dynamic information are shown.
Keywords: asymmetric Petri nets, flexible manufacturing systems, heuristic searches, scheduling algorithms, symmetric Petri nets.