Deadlock prevention and deadlock avoidance in flexible manufacturing systems using Petri net models

Deadlocks constitute an important issue to he addressed in the design and operation of flexible manufacturing systems (FMS’s). In this paper, we show that prevention and avoidance of FMS deadlocks can he implemented using Petri net models. For deadlock prevention, we use the reachability graph of a Petri net model of the given FMS, whereas for deadlock avoidance, we propose a Petri net-based on-line controller. We discuss the modeling of the General Electric FMS at Erie, PA. For such real-world systems, deadlock prevention using the reachability graph is not feasible. We develop a generic, Petri net-based on-line controller for implementing deadlock avoidance in such real-world