An integrated modeling approach for shop-floor scheduling and control problem of flexible manufacturing systems

Abstract

Increasing automation and complexity of today's production systems affect the constraints of real-world shop-floor control and scheduling problems. To deal with these constraints, either the existing modeling and analysis techniques were improved or new scheduling approaches were developed. This study attempts to propose an object-oriented approach for modeling and analysis of shop-floor scheduling problem of flexible manufacturing systems (FMSs) using high-level Petri Nets (PNs). The graphical nature and mathematical foundation has made PN-based methods appealing in real-time scheduling and control of FMSs. In the proposed approach, we firstly construct an object-modeling diagram of an FMS and develop a heuristic rule-base to solve the resource contention problem then formulate the dynamic behavior of the system by high-level PNs. The modeling methodology is illustrated by an FMS, and the proposed rule-based system is compared with several dispatching rules with respect to part flow time and tardiness-related performance measures.