Online performance measurement for automated material transportation

Vehicle based overhead transportation systems are a widely used Automated Material Handling System (AMHS) solution applied in factories for 300mm and 200mm front-end wafer manufacturing. The track layout of modern AMHS shows the characteristics of a large transportation network. The stable delivery performance and the avoidance for these systems. The vehicle routing algorithms applied in the material control system or the transportation controller directly impact the delivery performance and the avoidance of congestions. We present an approach of how to measure online key transportation metrics. The approach can be used in order to optimize AMHS configuration as well as to provide accurate transportation delay times for factory wide lot scheduling and dispatching systems.