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The authors discuss the concept and design criteria for a framework that facilitates the performance assessment of shop-floo control systems. Their basic concept includes a simulation model that emulates the shop floo of a wafer fab, sends information to the control system, and receives information back from the control system. The shop-floo control system is realized as a separate module that interfaces to the simulator via a data layer that contains the current shop-floo status and the control information generated by the controller. The authors provide detailed information on how the simulation model and shop-floo control system communicate and how each system triggers events in the other system. They show how this framework supports the performance assessment of the shop-floo control system under consideration. They also present a prototype of the framework currently implemented in the course of the SRC/International Sematech FORCe project "Scheduling of Semiconductor Wafer Fabrication Facilities."

In this paper we present a simulation study of wafer fab ramp-up scenarios with the simulation software AutoSched AP. A generic factory model (MIMAC 1 from Int. SEMATECH) was adapted to simulate fab ramp-up scenarios. The model was customized to consider time phased modeling capability and time phased reporting. Additionally, an evaluation approach for the comparison of different ramp-up scenarios is presented. This approach helps to evaluate the ramp-up performance with different input parameters. A systematic variation of dispatch rules and lot sizes during ramp-up is shown

This paper gives an overview of advanced scheduling and dispatching policies for WIP (work in process) management within the wafer fabrication process. Additionally, the pros and cons of general WIP control philosophies are opposed. Several control policies are evaluated for the application in complex make-to-order environment such as ASIC production. Based on the real shop floor environment of Philips SMST and the currently used control policies a proposal is presented answering the following two questions:What are the requirements of tomorrow's WIP control systems applied in make-to-order wafer fabrication? How can these control policies be implemented and introduced on the shop floor using existing WIP control and scheduling systems?

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