As more and more enterprises decide to introduce or to change IT systems, the implementation process becomes an important undertaking in many organizations. However, not all implementations are uniformly successful. The reasons behind problems vary and should be analysed from the perspectives of technology and management. Hence, it is important to understand what is necessary to ensure a successful IT system implementation. The paper takes an in-depth look at the issues behind the process of IT implementation via a case study methodology. It examines four cases of implementation of the fine recovery system, that were successful but not equally assessed by clients. The authors compare these implementations from both the client and the supplier perspective using data collected with a questionnaire survey and interviews. The authors try to explore the differences between these implementations and to identify their core issues. Some actions that can help improve troublesome implementations are recommended.