Control Methodology for FMS

Intelligent real-time control of a flexible manufacturing system (FMS) is a complicated task. The scheduling of machines and routing of jobs are nonpolynomial problem that have to be solved fast and accurately to materialize the advantages of an FMS. Such control is done hierarchically where in the cell level, part routing is considered and in the workstation level the equipment control strategy is reviewed. Two methods of controlling an FMS are described, one for each level. The first one, which controls the workstation equipment, conducts a decision table in which the system states are correlated to the decision variables. The second method, that routes parts between the machines in the cell, uses a knowledge base that stores facts about the facility, and recongnizes evidence to generate a decision. Both methods are presented with are presented with results from simulation experiments..