On real-time scheduling policies for flexible manufacturing systems

The authors consider a model proposed by J.R. Perkins and P.R. Kumar (ibid., vol.34, no.2, pp. 139-148, Feb. 1989) for real-time control of flexible manufacturing systems. In this model, a machine can process a finite number of part types at specified rates, but only one part type can be processed at any given time. To process multiple part types, the machine uses a feedback rule to switch, from time to time, from one part type to another. Such switches incur a setup time of delta time units during which no parts are processed. By introducing the notion of idling, the authors derive a lower bound on the performance, as measured by average buffer size, of any stable feedback scheduling policy for a single machine. >