A Hierarchical Fuzzy Control System For Short-Range Planning And Scheduling
Luís Custódio, Carlos F. Bispo, J.J.S. Sentieiro · 2005
This paper presents a non-classical approach supported in fuzzy theory to solve short-range planning and scheduling problems. The proposed method is based on the hierarchical structure presented in [8, 9]. It has three control levels, each one of them responsible for a different production problem with a different time scale. The higher level defines the safety stock levels used to compensate future resource failures. The loading rates are computed by the middle level using a predefined demand target and the stock levels supplied by the upper level. This is accomplished using a method based on fuzzy control concepts. Finally, the lower level controls the flow of parts between the resources, deciding at each time instant which part will be produced by the resources available. These decisions are generated using a modified version of the Yager's fuzzy decision method. Simulation results for two different production systems are presented, showing that the proposed method achieves a good p...