Fuzzy admission control and scheduling of production systems

Abstract

Two outstanding problems of admission control and scheduling in networks with three and two workstations respectively are solved using fuzzy logic. In the first case we have one workstation with two parallel ones. A reward is earned whenever the first stage accepts a customer and a holding cost is incurred by a customer in the queue in the second stage. The class of customer to be served next by the first stage is dynamically selected so as to maximize an average benefit over an infinite horizon. In the second case there are two parallel machines and three arrival processes generated by independent Poisson streams. Each machine has its own queue and receives parts from its own arrival stream. The third arrival stream consists of parts with resource demand on both machines. Each customer pays a holding cost per unit time in the system. Again, the scheduling policy is specified which minimizes the average cost. The fuzzy models are new in this context and tackle problems that cannot be solved by analysis.