21. Graphically, places in a Petri net may contain a discrete number of marks called " tokens ". 22. In this respect, " M " extends the concept of configuration for elementary nets to Petri nets . 23. Its main purpose is to automate modelling operations on Petri nets such as merging, creating, and connecting nodes. 24. In recent years a number of attempts have shown that Petri nets can contribute to the development of business process integration. 25. CPN preserve useful properties of Petri nets and at the same time extend initial formalism to allow the distinction between tokens. 26. The event segments are used to define Timed Event Systems such as DEVS, timed automata, and timed petri nets . 27. His early research is characterised by work on topological automata and systems, decision problems and structural properties of Petri nets . 28. Petri nets therefore can be used to model certain business processes with corresponding state and transitions or activities with in and outputs.29. "' CPN-AMI "'is a computer-aided software engineering environment based on Petri Net specifications. 30. "' PetriScript "'is a modelling language for Petri nets , designed by Alexandre Hamez and Xavier Renault.
