Statecharts as Protocols for Objects

For the specification of object-oriented systems, usually several models representing different views are developed. The necessary integration of views is often delayed until implementation, but for validation and verification purposes the merging of views is desirable already during specification. Motivated by this, a model of objects is proposed in which the different views on an object are regarded as independent and well-connected entities that are encapsulated inside of it. Reference nets, a powerful high-level Petri net formalism, are used as an underlying uniform modeling technique for objects and the two views on them considered here — protocols and functional parts. Protocols are defined as statecharts and mapped into Petri nets. Models become executable by utilizing Renew, a tool for drawing and simulating reference nets. In an example, the main ideas of the suggested approach are clarified.