Slicing and reduction techniques for model checking Petri nets

Model checking is a method to validate the correct functioning of a piece of hardor software. Specifications are expressed in temporal logic. A model checking algorithm determines automatically whether or not the checked model satisfies a given specification by examining the model’s state space. In their basic form model checking algorithms explore the state space exhaustively. As the number of states may grow exponentially in the size of the system—which constitutes the infamous state space explosion problem—the development and application of methods to deal with huge state spaces are crucial. Petri nets are a well established formalism to specify asynchronous systems that involve concurrency, parallelism and nondeterminism. They offer an intuitive graphical notation along with an abundance of analysis techniques. In this work we develop two Petri net reduction approaches to tackle the state space explosion problem for model checking. Petri net reductions are transformations of the Petri net that decrease its size. As a mean against the state space explosion problem for model checking they have to preserve temporal properties and reduce its state space. Petri net reductions can conveniently be daisy chained with other methods fighting state space explosion. The key idea for both of our approaches is that often parts of the net can be identified not to influence the temporal logic property, which usually refers to a few places of a net only. In the following scope(φ) denotes the set of places referred to by a temporal logic formula φ. For a given net Σ and temporal logic formula φ, both approaches determine a net Σ that contains at least scope(φ) and simplifies the remaining net such that Σ is equivalent