Formal models of execution function in shop floor control

Abstract

Computer integrated manufacturing (CIM) has recently received a great deal of attention as an effective strategy to improve manufacturing responsiveness and quality. CIM seeks to integrate the entire manufacturing enterprise through the use of an integrated set of computer systems. However, the evolution to CIM has been slower than expected. This can be directly attributed to the high cost of software development and maintenance and the difficulty in achieving the required levels of integration between systems. These problems are especially evident in the development of the central part of a CIM system, the shop floor control system (SFCS). The SFCS is responsible for planning, scheduling and controlling the events on the shop floor. An SFCS (performing some or all of the planning, scheduling and control functions), together with the associated shop floor equipment, used as a stand-alone system is often called a flexible manufacturing system (FMS). This chapter presents two related approaches to modeling the execution function in SFCS. Implementation experience involving the use of these models in a full scale manufacturing system is also provided.