A MATHEMATICAL MODEL FOR SEQUENTIAL BATCHING PROCESSING MACHINES SCHEDULING PROBLEM IN TFT-LCD PROCESS

摘要

In high-tech manufacturing, to enhance productionrnefficiencies, batch processing machines which can processrnseveral jobs simultaneously are commonly used for longprocessingrntime operations. In thin film transistor liquidrncrystal display (TFT-LCD) manufacturing processes, fourrnsequential batch processing workstations are involved inrnthe cell assembly process which is mainly used tornassemble TFT substrates and color filters. Four sequentialrnbatch operations make the batch scheduling problemrnbecome more complicated. In addition, no existingrnsolution algorithms are shown in previous research work.rnConsequently, in this paper, we propose a mixed integerrnprogramming (MIP) model for four sequential batchingrnprocessing workstations in which we consider thernconstraints of limited waiting time, maximal batch size,rnand setup time between two different product types. In thernproposed MIP model, to obtain the detail schedule forrnfour sequential batching processing workstations, wernconsider the objective function is to minimize total setuprntimes of bottleneck workstation on the premise ofrnsatisfying the throughput target. To demonstrate thernapplicability of the MIP model, a real-world examplerntaken from a cell assembly shop floor in a TFT-LCDrnfactory is provided.