The Study of the TOC-based Multiple-Integrated Dispatching Rule in Semiconductor Manufacturing
Date Issued
2004
Date
2004
Author(s)
Peng, Tse-Chang
DOI
zh-TW
Abstract
Job dispatch is an important issue in wafer fabrications. It affects system performance. However, few dispatching rules developed, in the past, focus on profit. Hou[2001] developed a TOC-based dispatching rule, named DTC (Dispatching by Theory of Constraints). Hou’s method based on the consumption of system resource can estimate the WIP cost and values. Based on the profit (the difference of values and cost) of the wafers, the job dispatching can then be assigned. Hence, DTC is superior to others from the profit viewpoint in a certain time-period. Can it meet other requirements such as due date, quality or/and minimum inventory? If it cannot, in the long run, DTC can never be a good dispatching rule from any view of points. Furthermore, in Hou’s study he uses FCFS to dispatch job when two jobs have the same profit. Instead of using wafer arriving time, it seems more effective to include due date, quality, or/and minimum inventory as the second and/or the third job dispatching criterion.
The main purpose of this study is to extend Hou’s simple-profit -based DTC to a multiple purpose dispatching method. Famous CR, MCR and FSMCT are included in the new method. CR is good in due date, MCR in low inventory, and FSMCT in quality. By simulations, several multiple purpose dispatching methods, by the combinations of DTC, CR, MCR and FSMCT, are performed. The simulation results indicate the best combination can effectively improve the performance of due date, quality and numbers of inventory.
Subjects
多重式
限制理論
派工法則
dispatching rule
multiple-integrated
theory of constraints
Type
thesis