Two types of extended RSNBs and their application in modeling flexible manufacturing systems

Abstract

In the former paper (Liu et al. Int J Adv Manuf Technol 41:66–74, 2009), a novel policy was proposed to prevent deadlocks in a class of flexible manufacturing systems (FMSs). This policy is based on the notion that each shared buffer is partitioned for storing different types of parts. Furthermore, A subclass of Petri nets, resource-shared net with buffers (RSNB), was defined to characterize this policy and model the controlled system. Two extensions of RSNB are defined in this paper. The first extension, which is called extended resource-shared net with buffers (ERSNB), permits the resources to be shared among different stages in one manufacturing process. The second extension, which is called resource-shared assembly net with buffers (RSANB), takes the assembly and choice operations into account. Both ERSNB and RSANB have a well property that each minimal siphon is exactly a minimal trap. It has been proven that an ERSNB or RSANB is live if and only if each minimal siphon is marked under the initial marking. Two well-known examples of FMSs are used to illustrate the proposed concepts and policy.