An algorithm for direct construction of complete merged processes

Abstract

Merged process is a recently proposed condense representation of a Petri net's behaviour similar to a branching process (unfolding), which copes well not only with concurrency, but also with other sources of state space explosion like sequences of choices. They are by orders of magnitude more condense than traditional unfoldings, and yet can be used for efficient model checking. However, constructing complete merged processes is difficult, and the only known algorithm is based on building a (potentially much larger) complete unfolding prefix of a Petri net, whose nodes are then merged. Obviously, this significantly reduces their appeal as a representation that can be used for practical model checking. In this paper we develop an algorithm that avoids constructing the intermediate unfolding prefix, and builds a complete merged process directly. In particular, a challenging problem of truncating a merged process is solved. © 2011 Springer-Verlag.