Petri net models and functional abstractions: applications to the design of automated manufacturing systems

The use of generic models in the synthesis of FMS systems, which allows for rapid modelling and analysis, does not ease the verification task difficulty. Even though generic modules can be verified separately, the verification of the interconnections between modules requires the whole model to be considered. A potential solution is to replace the generic modules with their functional abstractions which realise the external functional behaviour of these modules. The number of places and transitions involved in realizing the required functionality is, typically, a fraction of that used to represent complete components. This reduces the complexity of the components of the modelled system, and thus the complexity of the verification model. The verification task can then focus on the correctness of the interfaces, rather then on the internal nature of the components. In this paper, for a class of Petri net models, which can be used to represent the primary components of the AGV based FMS systems, extensions to the author´s previous method (1994) that allows one to systematically construct functional abstractions are presented.