EWFN - A Petri Net Dialect for Tuplespace-Based Workflow Enactment

Petri nets are a formalism for describing systems where interactions between active components – so-called transitions – are modeled as exchanges of tokens over passive places. Whether a transition may fire is solely dependent on the availability of tokens in its incoming places; similarly a transition forwards control to subsequent transitions by storing tokens in their respective input places. This interaction model of strong decoupling through local actions and local effects makes distributed systems modeled via Petri nets highly extensible. In this paper, we present the syntax and semantics of a model that leverages the extensibility provided by Petri nets for representing BPEL processes in a way that enables their distributed and decentralized execution using tuplespace middleware. Said middleware implements the proposed Petri net dialect and therefore allows for direct, distributed execution of the modeled processes.