近一、二十年，生產全球化的趨勢開創了蓬勃的製造服務產業，製造廠商經常主動接觸品牌產品公司，提供生產服務，建立供應鏈上下游協作關係，但是產品公司通常採取多元委外方略，將生產委託給多家廠商，本文探討這種「產品設計公司－產品製造公司」多方企業組織結構內一種產能服務能耐的現象與衍生的競爭問題。在高科技製造領域，產品需求非常易變、產能投資成本高，製造廠商進行產能投資面對極大的企業風險，若產能擴充保守，產能供應不足的可能性往往成爲產品公司關切的風險，因此產能預備是服務能耐的一個要素，可作爲製造廠商的服務競爭策略。本文以產能服務的能耐差距爲基石，建構產能服務競爭的理論分析方法，這個方法的第一個部份是一個新穎、以能耐差距爲要素的需求分配法則，第二個部份是雙佔廠商的產能競爭模式。本文先推導雙佔廠商在競爭情境的反應函數，再證明產能策略存在單一均衡點，最後利用產業數據，以數值範例推理廠商的產能競爭行爲：當跟隨廠商採行激進的產能擴充，領導廠商會有相對保守的反應，以避免產業總供給過剩，並任由跟隨廠商承擔易變需求所隱含的風險；而當領導廠商採行激進的擴充，跟隨廠商可能同樣採取激進行爲，以防止其客戶流失，但是總產能供應將因此增加，兩家廠商的產能利用率將下降，對利潤或成本結構較弱的廠商最爲不利。

Globalization of production has ushered in vibrant manufacturing service industries. Many high-technology manufacturing service firms frequently take initiative to forge supply relationships with product firms. In these engineering-manufacturing chains, certainty of capacity supply is an important concern as conservative (insufficient) capacity expansion is frequently prompted by high uncertainty of demand and investment risk. Capacity strategy has traditionally been discussed from a manufacturer's perspective to time or size the investment, or to compete in a game setting. In the era of manufacturing services, customers' concern of capacity certainty should be included as an important factor in formulating a capacity strategy. This paper presents a mathematical analysis of this new aspect. Uncertain demand is modeled as a lognormal random variable. A novel service-based demand rationing rule is developed for a duopoly of differentiated prices. Reaction curves and equilibrium of capacity strategy are derived and competition behavior is analyzed.