在知識經濟的時代，資訊科技的無形價值引發學者及管理者的廣大興趣。企業IT資本成為企業競爭力、持續力的重要關鍵因素之一。IT資本通常隱藏在結構資本內，成為IT投資或營運績效的指標。目前有許多針對企業IT資本基礎結構角色的論點。但是我們針對在複雜環境、資源互相影響下，如何管理IT資本卻是甚少瞭解。本研究利用互補觀念，強調IT資本與其互補資源管理以達到企業持續競爭力的重要性。經由CRM系統的多重個案分析，我們瞭解CRM系統價值與互補資源（包含流程、結構、能力及文化）管理的關係。本研究的發現可以貢獻在IT資本管理及IT資本相關互補資源的應用。 The intangible value of information technology (IT) has triggered researchers' and managers' interests in the knowledge-based economy. It has been increasingly emphasized that firms' IT capital is one of the key determinants of business competitiveness and sustainability. IT capital has usually been hidden in the structural capital as an indicator of either IT investment or the operational performance. There are a number of theoretical arguments about the infrastructural role of a firm's IT capital but limited understanding of how this kind of intellectual capital should be managed in a business environment in which complex resources interplay. Applying the complementarity concept, this study highlights the importance of the management of resource complementarity with IT capital in order to deliver sustainable competitiveness. Through multiple case studies of customer relationship management (CRM) systems management in five financial organizations, we analyze the value of customer relationship management systems in relation to the management of complementary resources, including process, structure, capability, and culture. The findings contribute to a better understanding of the management of IT capital and a better application of the complementarity of IT-related resources.