The customization of enterprise resource planning (ERP) systems can increase the local benefits of end- users. However, it also increases the costs of development and implementation for every system upgrade. Finding balance is a common challenge. A critical element in the process is organizational change management (OCM). This paper reports the pre-implementation phase results of a longitudinal case study on the relation between OCM and customization at a leading international automobile systems manufacturer: Hanover Auto Systems. The study uses a two- pronged approach: first a qualitative assessment, followed by the development of a research model. The interviews with key project managers indicate that OCM communication on the vision and ERP details is a major challenge and influences ERP customization expectations in the pre-go-live stage. Based on this finding, a research model was conceptualized on ERP customization expectations and local unit benefits. The results of a survey questionnaire to the project managers show that local units inherently expect OCM to increase customization for their benefits. Problems with the OCM vision and organizational support cause OCM problems. This in turn lower the expectations for wanted customization, because users become unware of the details of new ERP systems. The implications of our findings are discussed.