Enterprise systems hold a large promise for organisations to enhance their strategic position. However, adoption and implementation of enterprise systems is not without problems. Many problems have been reported in the literature with implementation of new technology, many of which seem to reoccur over and over again. It seems difficult for organisations to learn from previous experience and successfully organise and manage complex dynamic projects like an enterprise system implementation project. Although current project and change management methods offer support in organising and managing complex projects, more is needed to increase insight into the specific situation at hand. In this chapter, research is presented aimed at collecting knowledge on the dynamics of enterprise system implementation projects. The knowledge can serve to increase awareness of potential risks and pitfalls in specific new enterprise system implementation situations. To make the knowledge accessible, a tool has been developed for assessing a start-up situation of an enterprise system implementation project in an organisation. The key concept in this assessment is the level of mutual alignment between various organisational aspects of the business in which the system is implemented, the enterprise system, and the implementation project.