Modeling the master production scheduling system with downgraded products for a TFT-LCD module factory

At the end processes of TFT-LCD supply chain, the LCM module factory takes charge of the process of assembling products, and its production planning needs to consider various products with different graded TFT-LCD panels while meeting customers´ specific qualifications, including lowest acceptance rates for quality and zero-bad-defect quantity. Since the machine setup time of the bottleneck workstation in the factory is very long, it is of practical importance to design an appropriate production scheduling with concerns about times of machine setups and different grades of TFT-LCD products. This paper proposes a production scheduling system that comprises the material planning with downgraded products as well as the bottleneck scheduling for a LCM module factory using make-to-stock production, and solves the system based on integer programming. Experimental results show that the system not only is capable of reducing the number of setup times, but also performs well in efficiency of preparing critical materials. From a practical aspect, such a system can support production managers to plan their production scheduling effectively.