Knowledge-based process planning in surface mount technology

Process planning in printed circuit board (PCB) assembly using surface mount technology is scheduling-intensive. Artificial intelligence based techniques used in computerized planning and scheduling systems in other industries can be extended to PCB operations. These techniques include blackboard architectures, object-oriented programming systems, and nonmonotonic reasoning systems. These techniques have been blended in a unique architecture of blackboard systems that communicate via object-oriented messages to arrive at the set of decisions that constitutes a shop-floor process plan and schedule. The methodology was specialized to the assembly of PCBs using surface mounted components in a high-variety/low-volume product mix. The assembly facility was represented as a hierarchical object of product, process, and organizational knowledge. The integrated process planning and scheduling system that has been developed overcomes the limitations of previous computer-aided process planning systems for electronic assembly