本研究以一家晶圓代工廠商為研究對象，蒐集六個月的機台別與生產批量别資料，實證檢視製造彈性對生產品質、生產週期時閒、設備生產力與生產成本之影響。不同於過去研究，以外部彈性（例如：產品組合彈性、新產品彈性等）為研究重心，本研究以內部彈性為研究範疇，涵蓋機器彈性與路徑彈性兩類彈性型態。實證分析結果顯示：在晶圓代工的製造環境中，路徑彈性不僅有助於生產週期時閒的縮短，也對品質績效具有顯著的正向影響，而機器彈性雖有助於設備生產力的提昇，但對生產品質則有顯著的負向影響；在財務績效方面，本研究則發現機器彈性與路徑彈性均有助於生產成本的降低。此外，本研究並發現：製造彈性與設備生產力、生產週期時閒及生產成本之閒存在非線性關係，並呈現報酬遞減的趨勢，隱含：極大化製造彈性並非最佳，有限的彈性水準即可達到最大的彈性利益。

This study examines the impact of manufacturing flexibility on production quality, cycle time, equipment productivity and production costs within the context of semiconductor wafer fabrication facilities. To fill the gap in existing research, I attempt to study internal flexibility, rather than external flexibility (e.g., product flexibility, mix flexibility). Two types of internal flexibility are selected, which are machine flexibility and routing flexibility. Using six-month machine-level production data and lot-level data from one semiconductor wafer fabrication company, this study investigates the impact of manufacturing flexibility on production performance and production costs. Empirical results suggest that greater routing flexibility has a significant positive impact on quality and time performance. As for machine flexibility, it has a significant positive impact on equipment productivity, but has a significant negative impact on production quality. Moreover, I find support for the hypotheses that routing flexibility is negatively associated with production costs and that machine flexibility is helpful in improving cost performance. Besides, the two flexibility types not only directly impact production cost but also indirectly affect production cost through time performance. Furthermore, I also find a non-linear relation between manufacturing flexibility and equipment productivity, cycle time, and production cost. This implies that maximizing the level of manufacturing flexibility is not necessarily optimal for firms. Limiting the flexibility level may actually have the greatest benefit.