具單一瓶頸的製造單元之群組排程程序

Abstract

於單元製造環境中，單元所加工之工件具有相似的製程需求，導致負荷不均衡的狀況，因而產生瓶頸相關問題。為解決具有瓶頸現象之單元排程問題，本論文結合瓶頸管理之觀念以及群組排程，提出一以瓶頸為基礎之群組排程（BGSP），以降低所有工件完成時間（makespan）。為了評估BGSP之績效，針對流程型與零工型製造單元，設計一四因子實驗，實驗因子包括：整備相對於加工時間之比例、工件族數量、瓶頸相對於非瓶頸機器之負荷比例與排程方法。模擬結果顯示，不論單元型態為何，負荷不均衡之問題對於績效表現的影響最顯著。在排程績效表現上，BGSP不僅是所有工件完成時間最短之排程方法，且在各種實驗狀況下，績效表現亦相當穩定。實驗證實對於負荷不均衡之單元，運用瓶頸管理於群組排程中，確實可提昇製造單元之績效。

Load imbalance and bottleneck phenomenon frequently occurs in a cellular manufacturing (CM) environment due to the similarity of process requirements. This study presents a bottleneck-based group scheduling procedure (BGSP) that integrates bottleneck management with group scheduling for cellular manufacturing with a bottleneck. The BGSP attempts to fully utilize the bottleneck machine and minimize the makespan. Also designed herein are a simulation model and a four-factor factorial experiment for two different cells. Experimental factors including setup-to-run time ratio, number of part families, bottleneck-to-nonbottleneck load ratio, and scheduling procedures are examined as well. The impact of the factor, bottleneck-to-nonbottleneck load ratio, on performance is most significant among all four factors. The BGSP possesses the best average makespan and more robust than available procedures. Results in this study demonstrate the practical nature of bottleneck management on group scheduling in cellular manufacturing systems.