Traditionally, government agencies are organized vertically around departments. Many local government agencies are looking for ways to develop an integrated architecture. Many architectural methods are available, however, they remain often abstract, provide limited support for the translation of the concepts to a concrete situation, and have limited visualization support to create a shared understanding. In the research presented in this paper we describe the development of a reference enterprise architecture for a municipality using action research. Our development approach is based on modeling the interdependencies among, and within organization, business process, and application layer. We used discrete-event simulation, and animation to provide insight in the existing situation, and develop and create a shared understanding of the reference architecture.