This paper deals with the development and use of business cases in support of cross-organizational enterprise resource planning (ERP)-enabled e-business integration initiatives. In order to ensure that such a project starts successfully, we will focus on preimplementation activities. We propose a set of business case guidelines that emphasize the importance of benefits management during ERP implementations. Categories and Subject Descriptors H.4.2 [Information Systems Applications]: Types of Systems – Decision support D.2.9 [Software Engineering]: Management – cost estimation, time estimation General Terms Management, Measurement, Human Factors, Standardization. Keywords Business Case, ERP, Cross-organizational, E-Business, Benefits.