An integrated process planning and production scheduling framework for mass customization

Process planning and production scheduling are two important issues in the manufacturing system. In combination, they determine how and when to produce which products with what available resources. Traditionally, process planning and production scheduling are considered as two isolated tasks and conducted by separate departments with long time gap in manufacturing enterprises. Such isolation and time gap have become major limiting factors to fully utilize the manufacturing resources, and adversely impact on overall productivity. In Mass Customization environment, the isolation and time gap between process planning and production scheduling have become even more significant problems. The motivation to integrate process planning and production scheduling is developed to address such problems by unleashing the under-utilized resource flexibility. The objective of this research is to develop a novel framework to integrate process planning and production scheduling tasks in Mass Customization environment following make-to-order policy. In this framework, one novel data structure called 'Generic Production Capability' or GPC is proposed to model the production capabilities of resources on meta-level. Process planning in the framework will employ one declarative processing mechanism to generate process plans capturing all feasible production routings for the released customer orders on demand by linking and configuring proper sets of GPCs in sequence, but leave the selection of routing to production scheduling stage. Production scheduling will combine composite dispatching rules and simulated annealing approach to make fully use of the flexibility of alternative routing selection to derive more globally optimized time schedule to fulfill released customer orders (implication of integration in this research). Since the process plans are generated on demand with regard to status of resources on the shop floor, frequent modification of process plans on the shop in current practice is thus avoided. Moreover, the proposed framework also releases process planners from construction of process plans for a huge number of product variants offered to customers. As a result, tremendous amount of process planners' efforts can be saved