Uebernickel, FalkFalkUebernickel2023-04-132023-04-132006-03-01https://www.alexandria.unisg.ch/handle/20.500.14171/83134The guidance of the internal customer is a major challenge for the IS department of T-Mobile. In order to understand and improve customer guidance, it is necessary to study past IS projects, and analyse good as well as bad practices in guiding the internal IS customers. Learning from this, helps to improve future IS projects in terms of internal customer guidance. This paper describes the Dolphin project concerning the strengths and weaknesses of managing internal customer requirements. The different project episodes are especially analysed according to the question of how IS and internal customers interacted and how both parties dealt with formulating requirements. The case study's aim is to deliver five key messages for improving the understanding and guiding of internal customers.enCCIIMcase study