An adaptive multi-parameter based dispatching strategy for single-loop interbay material handling systems

The automation of interbay systems in 300 mm semiconductor wafer fabrication systems (SWFSs) is complex due to the dynamic, stochastic and mass transportation demands, transportation deadlocks, and vehicle blockages. An adaptive multi-parameter based (AMP) dispatching policy is proposed to obtain better performance of the interbay material handling systems and SWFSs. The system parameters, including vehicle's distance, lot's due date, lot's waiting time, and lot's origin-destination buffer status parameters are simultaneously considered, and the multi-parameter's weight coefficients are adjusted adaptively by Takagi-Sugeno fuzzy logic method. With experimental data from an interbay system of 300 mm SWFSs and running simulation experiments, it is demonstrated that the proposed approach has better performance in terms of cycle time, throughput, due-date satisfaction rate, and vehicle utilization compared to conventional single- and multi-attribute dispatching methodologies.