Petri Net Modeling in Flexible Manufacturing Systems with Shared Resources *

In this chapter, the authors develop a Petri net model of production routings and resource allocation in a flexible manufacturing system (FMS) with shared resources, which they call the R²PN model, and focus on the deadlock avoidance problems in the system. A FMS is composed of multiple subsystems such as machines, transport systems, and buffers, which must be controlled by a computer to achieve the production goals. The authors introduce the concept of D-structures and explore some of their basic properties, as well as characterize the liveness of the system in terms of D-structures. A D-structure is defined to capture the characteristics of the circular wait chain in the system. The authors address the deadlock avoidance problems by introducing the restrictive controller. They utilize Petri nets to model the dynamic behavior of the production operations and resource allocation of automated manufacturing systems.