Object-oriented design of FMS control software based on object modeling technique diagrams and Petri nets

Central software is very important to realizing the full benefits of flexible manufacturing systems. This paper highlights the difficulties in developing such software and proposes an object-oriented design (OOD) method using object modeling technique (OMT) diagrams and Petri nets (PNs). OOD is used to design reusable and easily maintainable software. OMT diagrams are used to represent explicitly different kinds of static relations, such as generalization, aggregation, and association, among the objects in an FMS. PNs are used to model the dynamic behavior of the objects and the entire FMS and to conduct performance analysis. The use of PNs also leads to a method to identify the data structures and operations of software objects. The proposed method is illustrated through an FMS example. Its capability to support reusability, extendibility, and modifiability of the resulting control software design is also demonstrated when the FMS specifications change.