The main target of this thesis is to implement the project management processes of Softcom-Int, which is a software development house, so as to reach the capability level 3 according to CMMI-Dev v1.3. The capability level 3 requires the processes to be well-defined and controlled, using statistical and quantitative techniques, throughout the project lifecycles. The structure of this thesis is divided to the theoretical part and the practical part. The theoretical part begins with the first chapter, which contains a brief description of Softcom-Int, including its operations, organizational structure and future plans. In order to be aligned with all the big organizations, it was decided the project management processes to be designed based on a worldwide ANSI standard for project management, the PMBOK. PMBOK extensively describes all the project management processes, the available techniques used by the best project managers in the world and can be used as a guideline throughout the lifecycle of a project.