The thesis focuses on developing a new approach to improve organizational project performance. This approach is based on a conceptual model giving a cognitive representation that enables the organization to build and adapt the items affecting the project performance. The model consists of three parts. The principles are the prerequisites that the leaders of the organization and people with coordination role must comply with. The concepts are definitions, ideas and mental constructs intended to be the model basis. The progress areas are made of issues and sub-issues that should be treated in a balanced way. This model has been used to create a method for organizations undertaking regularly internal projects. In the duration of the thesis, the method cannot be tested in actual situations.
