PRIAM - POLITE RESCHEDULER FOR INTELLIGENT AUTOMATED MANUFACTURING

This paper considers the problem of rescheduling in a decentralized ma nufacturing system, Flexible manufacturing systems must be able to res pond to unexpected disruptions, including schedule disruptions, Howeve r, when a cell controller in a decentralized system responds to a disr uption, it may disrupt some other cell, because the actions taken at o ne cell may have some consequence at another cell, In the approach we propose, a controller at a disrupted cell tries to respond in a way wh ich is likely to be least disruptive to other cells, through negotiati on with controllers at other cells, This approach, which we call ''pol ite replanning,'' has the advantage of retaining much of any original distributed plan, while avoiding wide propagation of the disruption th rough the rest of the system, We apply this concept to the domain of d istributed factory rescheduling, and describe PRIAM (polite reschedule r for intelligent automated manufacturing), a ''polite'' rescheduling architecture which is currently under development, Simulation results show that the use of negotiation in ''polite'' rescheduling prevents t he wide propagation of disruption from an initial local disruption.