Non redundant siphon control in ordinary Petri nets

In the Petri net framework deadlock avoidance policies based on siphon control are often employed, since it is easy to specify generalized mutual exclusion constraints that avoid the emptying of siphons. However, such policies may require an excessive computational load and result in oversized control subnets, due to the redundancy in the control conditions derived from siphons. In this work, a simple approach is proposed that provides minimum size maximally permissive controllers, thanks to a convenient classification of minimal siphons. Some examples are provided to demonstrate the feasibility of the approach.