產能投資時點與投資規模方法之比較研究

Abstract

高科技製造產業具有產品需求不確定、產能投資成本高，技術更迭快速等特性，在這樣的環境，經營風險高，加上產業景氣循環現象明顯，產能供給與需求經常發生失衡，而供需平衡與否為廠商獲利的主要因素之一。在產業環境中，需求是無法被控制的不確定因素，因此可控制的供給面便成為獲利的關鍵，故廠商的產能投資與策略應用變得重要，不僅決定廠商經營獲利，更會影響其長期競爭力。 多數產能投資策略的問題可以分為產能就緒時點(timing)和產能規模(sizing)決策兩種。就緒時點的決策為在什麼時候建置產能，其決策變數為時間；產能規模的決策則為在固定的時點下，決定要建置多少量，決策變數為數量。 本文為產能規劃方法的比較研究，針對就緒時點和規模決策模型提出一個公平的比較方法，以瞭解在如半導體製造產業的不確定環境中，各產能策略的規劃效果與行為表現，與不確定因素對於規劃績效的影響。而半導體製造產業中影響產能規劃不確定的因素有很多，諸如：需求的不確定、製造技術的不確定等，本文著重在探討需求的變異對於產能規劃方法選擇的影響。得到的結果為，在高度不確定的環境下，相較於產能規模決策，以產能就緒時點模型規劃有較好的績效表現。且就緒時點模型是較積極的產能投資策略；而規模決策模型為較保守的策略。

High-tech manufacturing industries are faced with uncertain product demand, high capacity investment cost, and rapid technology advancement. Also the notable business cycle often makes the demand and supply imbalance, thus increasing the operating risk. And the imbalance of supply and demand is one of the main factors that influences the manufacturer’s profit. However the uncertain demand is the factor that can't be controlled, therefore the controllable supply become the key to profit. Hence, the capacity investment decision of the firm will determine its profitability and long term competitiveness. Most capacity investment problems study the timing and sizing of capacity. Timing strategies decide when to build capacity and its decision variable is the “time”. And the sizing strategies decide how much capacity to build, the decision variables is “volume”. To time, or to size, that is the research question of this thesis. This study proposes a fair comparison method to comprehend the performance and behavior of the two capacity strategies. There are many uncertainties of semiconductor manufacturing industry, such as demand and technology. This study focuses on the effect of the demand variation upon the choice of capacity planning methods. Results obtained in this study are the timing model has a better performance in highly uncertain environment, and it is a more active capacity investment strategy rather than sizing model is a more conservative one.