A study on real-time scheduling of holonic manufacturing systems (5th report, estimation method of future status without decision criteria of other holons)

This paper deals with a real-time scheduling system of the holonic manufacturing systems (HMS). In the previous papers, real-time scheduling processes have been proposed based on the utility values of the candidate holons. A simulation based procedure has also been implemented to estimate the future status of HMS and to determine the utility values based on the estimated future status. However, it was assumed that the simulation models for estimation include the model representing the decision criteria of all the holons. A new simulation based real-time scheduling method is proposed, in the present paper, to improve the estimation process, which enable all the holons to estimate the future status of the HMS without decision criteria of other holons. An estimation process is developed for the individual job holons and resource holons to estimate the future status of HMS through the simulation. Some case studies of the real time scheduling are carried out to verify the effectiveness of the proposed method. It is shown, through case studies, that the proposed methods are effective to improve the objective function values of the individual holons.