A process model for implementing lean development in project management. The model is based on the experience that development projects are too complex for a comprehensive plan. Therefore, during the course of the project, intermediate results are generated in order to develop and improve the product as well as developing the planning iteratively and incrementally. The empirical improvement is based on transparency, review and adaptation. The Scrum Framework comprises the Scrum team with three roles, the product owner, the development team and the Scrum master. The Scrum team creates transparency regarding progress and intermediate results for the stakeholders.