We draw on information systems (IS) implementation, business process reengineering, and relationship management research to identify specific interventions that contribute to successful implementation of Customer Relationship Management (CRM) system projects. These interventions are examined across multiple cases, which depict varying levels of performance outcomes. The analysis not only confirms the important role of top management found in early studies on IS implementation and information integration, but provides a more granular assessment of these executive level interventions. The study also shines light on the role of CRM system characteristics and cooperative cross-functional and inter-organizational relationships in facilitating successful implementation of CRM systems. Researchers and managers need to consider these interventions in the context of information systems that not only impact multiple functional units but also external business partners. The results of the study provide managers with insights into areas where they can successfully intervene to manage the behavioral aspects of CRM system projects, make effective resource allocation decisions, and better plan for system functionality and structural issues. The propositions derived from the data will provide scholars with impetus for further research in clarifying the formula for successful CRM system implementation.