Abstract
It is desired that a deadlock control policy for automated manufacturing systems (AMS) is maximally permissive. However, its tractability issue remains open, and this work addresses this important issue. It models AMS with a resource-oriented Petri net (ROPN) and presents a necessary and sufficient condition under which there exists a one-step look-ahead maximally permissive control policy for deadlock avoidance in AMS. It further identifies some conditions under which a one-step look-ahead maximally permissive deadlock control policy exists for a single-capacity system. The conditions can be conveniently examined by using the developed ROPN model.