This thesis focuses on the internal problems for companies changing customer service system and how to best avoid these problems and make the implementation of the new system as efficient as possible. The reason for focusing on the customer service systems was since more and more companies are transcending to e-commerce and having some form of customer service is common. As the technology is changing so does the requirements for the system and thereby companies are in need for constant change. The problem area is wide and the results can be applied to almost any company undergoing changes of customer service systems. In order to find the internal problems and how to avoid these to efficiently implement the new system, interviews were carried out with companies that had undergone some form of change in their customer service. Theoretical studies were also carried out in order to confirm the interviews. The results of the study were that companies need to involve the affected employees and work with employee involvement. Doing otherwise would in many cases make the employees resistant to change. Furthermore, the IT changes being carried out need to have a more humanistic perspective rather than technological perspective, as the case was. The main finding was that there was a clear connection between the level of employee involvement and the level of efficiency when changing to a new system. In addition, educating employees on the new system and information sharing about the system already before start would create efficient implementation.