A blackboard architecture for integrating process planning and production scheduling

As companies attempt to increase customization levels in their product offerings. move toward smaller lot production. and experiment with more flexible customer/supplier arrangements such as those made possible by electronic data interchange (EDI), they increasingly require the ability to (1) respond quickly. accurately. and competitively to customer requests for bids on new or modified products and (2) efficiently work out supplier/subcontractor arrangements for these products. This in turn requires the ability to (1) rapidly convert standard-based product specifications into process plans and (2) quickly integrate process plans for new orders into the existing production schedule to best accommodate the current state of the manufacturing enterprise. This paper describes the IP3S system. an Integrated Process Planning/Production Scheduling shell for agile manufacturing. IP3S is based on a blackboard architecture that supports concurrent development and dynamic revision of integrated process planning/production scheduling solutions along with powerful workflow management functionalities for "what-if" development and maintenance of multiple problem assumptions and associated solutions. The IP3S blackboard architecture is designed to support coordinated development and revisions of solutions across the supply chain. The architecture is further shown to facilitate portability and integration with legacy systems. IP3S has been validated in the context of a large and highly dynamic machine shop at Raytheon's Andover manufacturing facility. Empirical evaluation shows an average performance improvement of 23% in solution quality over a decoupled approach to building process planning/production scheduling solutions.