晶圓製造廠因應產品組合更動之快速生產規劃機制

Abstract

由於晶圓製造業所具有的高投資報酬率，吸引了各方投資者紛紛加入此一行列，形成百家爭鳴的局面；此外，製程技術的演進快速，使得一晶圓片上的產出呈現倍數成長，超出原先所預期者，造成整個產業供需失衡，競爭激烈程度可想而知。各家業者為了獲取顧客青睞，紛紛提出更好的服務來提昇競爭能力，而允許客戶適度調整所下訂單內容，即為當前努力方向之一。 對於此一課題，本文基於保障系統其餘客戶不受到過多干擾的前提下，提出了晶圓製造廠因應產品組合更動之快速生產規劃機制，以系統化的分析流程，來進行各項規劃、決策工作。首先，目標規劃模組透過數學方法估算客戶訂單調整要求下之各項目標水準，包含：生產週期時間、系統在製品量、以及訂單產出時間等，以作為更新主生產排程、細部排程資料的依據；其次，基於限制理論所述之理念－瓶頸決定系統產出，產能需求評估模組因而透過工單負荷導向排程法對瓶頸資源、關鍵資源產能負載，進行嚴密的監控，以避免製造系統發生瓶頸漂移的現象；最後，對於企業經營的目標－利潤、以及製造系統在進行生產時的彈性－寬裕度，整體評估模組同時評估此二項績效指標於產品組合更動前後之變化，作出最終允許客戶調整訂單與否的決策。 實驗結果顯示，本文所提之快速生產規劃機制除了能夠使得生產系統的達交績效不受到影響外，對於訂單異動的部分亦能夠設定一個可行的交期；此外，藉由產能需求評估模組所做之良好控制，對於以層級在製品量作為現場控制之製造系統而言，可將系統因產品組合比例轉換所造成的衝擊，降至最低。上述種種，展現本文於實際應用上之可行性與有效性。

Due to high profitability in wafer fabrication industry, many investors join this game in the recent years. Additionally, innovation of process technology also increases throughput in supply. Thus, wafer fabrication industry is in keen competition because of supply over demand. It is very important for manufacturers to provide more service or flexibility in this competitive environment. Among them, more flexible in order changeover for customers is the key issue. For the order change issue, this paper develops a rapid production planning mechanism, which contains these modules, for product mix changing through systematic analysis. When product mix change is requested, the target planning module update the performance targets(product cycle time, throughput, order due date) with an analytical method. These targets are the basis for setting master planning schedule and detail planning schedule. Then basing on the theory of constraint(TOC), capacity demand evaluation module monitors the loading of bottleneck and capacity-constrainted resources(CCRs) by order-oriented scheduling method. So as to prevent bottleneck from shifting. Finally, integrated performance evaluation module makes decision by evaluating the changes in the profit making and the slackness for meeting due dates after the changing of product mix. The case study shows that the rapid planning mechanism not only achieves the delivery targets, but also set an achievable due date for customers. Additionally, this rapid production planning mechanism also can decrease the impact from changing product mix in a shop floor control system, because the layer WIP level control is implemented in the capacity demand evaluation module. Thus, the rapid production planning mechanism proposed in this paper is effective and efficient.