考慮瓶頸漂移及多瓶頸情境之MTO與MTS混線生產環境下生產控制之研究

Abstract

在MTO (make-to-order)與MTS (make-to-stock)混線生產環境下，已知短期MTO的需求，且需求隨時改變，導致瓶頸資源可能發生瓶頸漂移及多瓶頸的情況下，本研究提出生產控制法則（MTS產品的投料與在製品在各工作站的派工優序）。該生產控制法則以MTO產品的達交率、MTS產品的產出率，及MTS產品的產出率與投料率的差異為主要生產績效考量。 該生產控制法則以避免瓶頸工作站饑餓的動態投料法則(TW-SA)控制MTS的投料。在派工部份，MTO加工批在各工作站的派工優序皆高於MTS加工批。然而，當瓶頸工作站的缺料程度高時，瓶頸工作站內的MTS加工批派工優序會高於MTO加工批以避免產能閒置。當瓶頸工作站的缺料程度不高時，一般工作站以SRPT派工法則決定MTS加工批間的派工優序，當瓶頸工作站有缺料之虞時，以SABT派工法則決定MTS加工批間的派工優序。 最後經由一案例驗證，本研究所提出的生產控制法則，在MTO產品的達交率、MTS產品的產出率，及MTS產品的產出率與投料率的差異都有很好的績效。

In this study, we consider a production system with hybrid MTO (make-to-order) and MTS (make-to-stock). Corresponding to customers’ demand, bottleneck machine of this production system may be shifting. To deal with the environments mentioned-above, we present an algorithm to make the decision rule about releasing and dispatching to enhance the delivery-rate of MTO and the outputs of MTS. To avoid the bottleneck idling, we develop a time window- starvation avoidance (TW-SA) rule to release the MTS lots timely. The MTO lots have the higher priority than the MTS lots in every work shop, besides that the bottleneck is going to idle. When the WIP level before the bottleneck machine is lower than the threshold, the dispatching priorities among MTS lots are determined by SABT dispatch rule. Otherwise, the dispatching priorities are determined by the SRPT dispatch rule. Simulation results show that the delivery-rate for MTO products, a high output-rate for MTS products, and a small difference between input-rate and output-rate for MTS products of the proposed algorithm are better than other representative algorithm in literature.