SCHEDULING MANUFACTURING SYSTEMS WITH WORK-IN-PROCESS INVENTORY CONTROL - MULTIPLE-PART-TYPE SYSTEMS

We have studied here the real-time production scheduling problem for m ultiple-part-type flow shops. The system under consideration consists of many machines and produces many product types. Each part goes throu gh the system following a pre-defined routeing and may visit each mach ine at most once. We consider three classes of activities: operations, failures or repairs, and starvation or blockage. The scheduling objec tives are to keep the actual production close to the demand and to red uce the work-in-process inventory and cycle time. A three-level hierar chical production control model is developed to regulate production fo r the manufacturing systems. The control policy specifies how to react to machine failures. It also tells how to allocate limited system cap acity among all the part types. It utilizes the material and the space in the storage buffers to alleviate the propagation of a failure to o ther machines in the system.