SEN State Event Net, Proposal to Enrich the Arsenal of UML Dynamic Diagram

UML in its release 2.0 is a powerful CASE tool for exploring the object universe. To design system dynamics, UML makes use of the interaction suite that counts now four diagrams replacing older sequence and collaboration diagrams of the 1.x versions. State and activity diagrams undergo cosmetic changes. Although these six dynamic diagrams are invaluable visual tools to express the behavior of any system, it would be very time consuming to use them to go through the whole design phase. Designers still need a more handy and chirurgical diagram to express algorithms at various granularity levels. Hereafter is a proposal of the State-Event Net called SEN, deriving from the Petri net. We keep only the original mathematical definition of the Petri Net and rebuild a new set of interpretation rules. Through our discussion, dynamic abstractions like action, activity, event, condition will be related to the message concept currently found in object engineering. The movement of monochrome tokens is further linked to system execution states. Parallelism is expressed naturally in SEN. The proposed network supports the decomposition process through subnets and control structures through IF then ELSE. With the triplet, class-object-SEN diagrams, a simple real-time application (microwave oven) is used hereafter to illustrate an alternative to currently used UML diagrams to design system dynamics.