A Hierarchical Planning and Scheduling Framework for TFT-LCD Production Chain

This paper presents a hierarchical planning and scheduling framework for Thin Film Transistor Liquid Crystal Display (TFT-LCD) production chain in an assembly-to-order (ATO) environment. The TFT-LCD manufacturing process comprises three sequential steps, namely TFT-LCD production chain: Array, Cell and Module process. Many special characteristics and constraints, such as product grade constraint, site-eligibility constraint and key material available constraint, are inherited in this production chain. The globally distributed nature of production planning and scheduling activities of TFT-LCD production also leads to an urgent need of an integrated planning and scheduling framework to balance supply and demand problems. The hierarchical framework divides planning hierarchies into three planning levels, identifying planning modules in each level in attempt to balance the supply and demand of the TFT-LCD production chain. Finally, an example is illustrated to demonstrate the relationship among the planning modules in the framework.