SCHEDULING SEMICONDUCTOR MANUFACTURING PLANTS

In many large systems, such as manufacturing systems and communication networks, whenever a resource becomes available, one has to decide which of several tasks contending for its attention should be performed next. Such problems are called ''scheduling'' problems. They are control problems of immense economic importance, and have often been formulated and addressed in an open-loop setting. Both to illustrate the types of problems encountered and to serve as focus, in this article we will address scheduling problems in a technological area of much topical interest - semiconductor manufacturing. Being of relatively recent origin, and organized differently from more traditional manufacturing systems such as flow shops and job shops, they are relatively less explored. They are also of significant economic interest, and much in the public limelight, and thus a fertile area for systems and control researchers. We provide an account of some problems in the area, as well as some suggested solutions.