Methodology to best extend AMHS for site expansion

As companies grow their capacity in multiple buildings there are increasing challenges with the automated material handling systems (AMHS) used to transport the wafers between two or more facilities. In some cases, the links used to perform these transports can become a constraint for the entire system. The problem grows more difficult as the expansion plan extends further into the future, making it harder to predict throughput requirements. This study discusses a particular throughput prediction tool as well as different approaches for evaluating designs. The approaches discussed include: integrated vehicle/conveyor model using static tool (Network approach), segregated dynamic models for conveyor/vehicle system, and integrated vehicle/conveyor dynamic model. The pros/cons of these approaches are discussed based on different use cases. The paper finishes by discussing the strategic advantages of factories performing expansion analysis early in the design of the factory and the importance to continue validating and improving these methods.