Tags:model checking, partial order reduction, stubborn sets, timed systems and timed-arc Petri nets
Abstract:
Partial order reduction for timed systems is a challenging topic due to the dependencies among events induced by time acting as a global synchronization mechanism. So far, there has only been a limited success in finding practically applicable solutions yielding significant state space reductions. We suggest a working and efficient method to facilitate stubborn set reduction for timed systems with urgent behaviour. We first describe the framework in the general setting of timed labelled transition systems and then instantiate it to the case of timed-arc Petri nets. The basic idea is that we can employ classical untimed partial order reduction techniques as long as urgent behaviour is enforced. Our solution is implemented in the model checker TAPAAL and the feature is now broadly available to the users of the tool in its latest release from January 2018. By a series of larger case studies, we document the benefits of our method and its applicability to real-world scenarios.
Start Pruning When Time Gets Urgent: Partial Order Reduction for Timed Systems