Faster Unfolding of General Petri Nets Based on Token Flows

In this paper we propose two new unfolding semantics for general Petri nets combining the concept of prime event structures with the idea of token flows developed in [11]. In contrast to the standard unfolding based on branching processes, one of the presented unfolding models avoids to represent isomorphic processes while the other additionally reduces the number of (possibly non-isomorphic) processes with isomorphic underlying runs. We show that both proposed unfolding models still represent the complete partial order behavior. We develop a construction algorithm for both unfolding models and present experimental results. These results show that the new unfolding models are much smaller and can be constructed significantly faster than the standard unfolding.