Enterprise Systems (ES) are often the largest and most important Information Systems (IS) an organization employs. Most ES are rented or bought as COTS (Commercial Off The Shelf) software. The use of COTS leads to a distinction between the development of the ES software—done by ES software providers, like SAP and Microsoft—and the implementation of ES software in a specific organization. ES implementations are often associated with problems like more costly to implement than anticipated and taking much longer to implement than anticipated. To improve ES implementation, ES providers increasingly support their ES software by, in part computer-based, implementation methodologies. The paper present an ES implementation evaluation framework called ES Implementation Methodology-in-Action. The framework integrates two complementary views: 1) a technology view, focusing on the formalized aspects as expressed in the ES implementation methodology (the content of the methodology), and 2) a structural view, focusing situational aspects as expressed by the implementers (the users of the implementation methodology) including implementers, implementation context, ES software and other individuals participating in the implementation project. Using document studies and interviews with implementers we show how the framework can be used to evaluate ES implementation methodologies. We evaluate one well-known ES implementation methodology: SAP’s ASAP.