Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
Date (from‐to) : 1993 -1995
Author : MORITO Susumu; IMAIZUMI Jun
This research project studied the effects of flexibility of modern automated manufacturing systems such as flexible manufacturing systems (FMSs) on their planning and control. In particular, the effects of flexibility on dispatching and schedule optimization have been analyzed in detail together with the effects of the reduction of the number of operations due to flexibility of machines.
Main results are summarized below :
(1) performance evaluation of dispatching rules in FMS
Performance of dispatching rules in FMS has been analyzed using detailed FMS simulator. Such factors as automatic material handling devices, finite number of pallets, finite size of buffer are included in the model, and their effects analyzed. The results show that processing-time-based simple (but new) dispatching rules give good performance when there exist no routing flexibility.
(2) "cooperative dispatching" to exploit flexibility
As routing flexibility, which is one o the key characteristics of FMSs, is not fully exploited under the traditional dispatching rules. To best utilize routing flexibility, a new scheme called Cooperative Dispatching has been proposed. Extensive simulation study shows that the cooperation between jobs and machines lead to improvement in performance measures such as due-date satisfaction, machine utilization, and job flow time.
(3) optimization of dispatching in FMS