A study on real-time scheduling of Holonic Manufacturing Systems (4th report, multi-objective optimization process for individual holons and whole HMSs)

This paper deals with a real-time scheduling system of HMSs (Holonic Manufacturing Systems). A scheduling process based on the utility values have been proposed and applied to the real-time scheduling problems of the HMSs in the previous report. It was shown that the proposed methods generate suitable schedules from the view point of the objective functions of the individual holons in the HMSs. A new real-time scheduling method is proposed, in the paper, to consider both the objective functions of the individual holons and the whole HMSs. In this method, all the pareto optimal combinations of the resource holons and the job holons are generated based on the objective function values of the individual holons. Following this, a most suitable combination is selected from the pareto optimal ones, based on the objective functions of the whole HMSs, such as total make span and total tardiness. It is shown, through case studies, that the proposed method is effective to improve the production schedules from the viewpoint of the objective functions of the whole HMSs in comparison with the previous method.