The goal of the research presented in this thesis is to examine software change management processes in order to identify essential change management problems and improvement requirements, to define processes which would aid in solving these problems, and give an example of how these processes can be implemented in practice. The subjects of the empirical research part of the study have been four software implemented companies which are in manufacturing process. Therefore, the focus of the study is on the processes which are used in developing and maintaining enterprise software. However, the literature study explores the problems of software change management from a more generic viewpoint, and can also be used as a reference for software development done for other purposes. Three of the four case studies are used in deriving the generic change management problem classes and process descriptions. These three case studies include only analysis of the change processes and problems related to them. The fourth case study is used for illustrating how the proposed problem classification can be used in change process analysis, and how the proposed process models can be instantiated.