On-line Planning and Scheduling for High-speed Manufacturing

We describe a real manufacturing problem that lies between job shop scheduling and temporal planning. The setting is online in the sense that new jobs arrive asynchronously, perhaps several per second, while plans for previous jobs are being executed. We formalize the problem as a variant of STRIPS extended with action durations and resources. We present a hybrid algorithm for this problem that combines techniques from partial-order scheduling and state-space planning. No domain-specific search control is used. Our current implementation successfully controls two prototype plants and our technology is anticipated to enable a new line of products. By integrating planning and scheduling, we enable high productivity even for complex plants.