A Petri-Net Approach to Refining Object Behavioural Specifications

In object-oriented system design, functional requirements are given and expressed as object interaction scenarios whereas implementation is based on classes of objects. One need to derive, from the given object interaction scenarios, object-based behavioural specifications which reflect exactly these object interaction scenarios for implementation purposes. In this paper, a Petri-net-based method is proposed for the refinement. It begins with specifying each object interaction scenario as a labelled Petri net with an AMG-structure. These labelled Petri nets are synthesised into a single integrated net which represents the integrated system. By making use of the special properties of the AMG-structure, the system can be effectively analysed on its liveness, boundedness, reversibility and conservativeness. Duplicate labels are then eliminated by fusing common subnets, so as to attain a uniquely labelled net on which individual object-based behavioural specifications are obtained as projections.