Most development projects have very complex dependencies regarding the tasks to accomplish. Process models offer the chance to incorporate the knowledge of many project managers into active projects. Bridging the gap between process models and project plans by defining such models precisely seems to be beneficial. In this paper, we show the benefits and highlight some of the interesting problems of integrating process modeling and project planning. We introduce metamodeling techniques to constrain the instantiation of the process model, so that structural aspects of the process plan can be derived. A small, consistent example is used throughout the paper to illustrate our approach.