Experience in simulating wafer fabs in the USA and Japan

The authors describe the extensive base of factory simulation experience in Japan and experiences with the new factory-modeling technology in the US. It is pointed out that factory simulation and performance analysis are valuable for the insights that they provide for obtaining rapid cycle times and the associated business advantages. Experiences in Japan that have highlighted the practical difficulties of applying the traditional techniques of queueing theory and simulation languages to the complexities of real factories are described. By comparison, Nihon Semiconductor´s experience with the new factory-modeling technology indicates that it overcomes these traditional difficulties. This modeling technology reduces the risks of undertaking a factory-performance analysis project. The new factory-modeling technology is now being successfully used in the US and Japan. Several examples of performance analysis studies at Nihon Semiconductor are described. A comparison of factory model results with factory operating data resulted in the development of a new characterization of labor efficiency