Compositional Petri net environment

This paper addresses the problem of application Petri nets to real-world parallel and distributed systems of industrial size. It is pointed out that in many cases a well-known hierarchy/refinement technique does not work perfectly. We suggest another solution based on an algebraic approach to Petri net representation. Two levels of compositionality are introduced. The first one, an algebraic level offers a designer a set of net operations which allow the user to to build complex Petri nets from simpler ones; these include the operations of sequential and parallel composition, choice, iteration, and disruption defined on the top of two auxiliary operations of synchronization. The second architectural level allows the user to manipulate with Petri net entities, where each entity is defined as a Petri net equipped with access points. Operations of entity composition through the access points are introduced. The suggested technique is demonstrated on three-level Petri net editor comprising basic, algebraic and architectural editors.<>