Governmental, organisational and technological developments are taking place at an increasingly rapid pace. Structures are becoming more flexible and new service and business models are necessary to maintain or improve the performance of an enterprise. This leads to an increasing need for enterprise governing capacity to allow managers to choose the right direction for an enterprise in the event of major changes, and to maintain and strengthen its coherence. In this book we describe how the General Enterprise Architecting (GEA) governing instrument is used to govern the enterprises' coherence. The central assumption of GEA is the direct relationship between the degree of coherence in an enterprise and the performance of an enterprise, making the governance of enterprise coherence a very interesting idea. Since the development of GEA, many enterprises have gained experience in applying the instrument; GEA has contributed in many different ways to the managing capacity of enterprises and has proven its value in solving complex enterprise issues. This has provided us with a wealth of information about the practical application of enterprise architecture according to the GEA philosophy. This book is intended for architects and other professionals who want to use 'enterprise coherence governance' in their practice. Solving enterprise issues is central to this book. We explain on the basis of a concrete roadmap how 'coherence' is made explicit and how this is used to develop a solution for an enterprise issue. We further elaborate on: ¿ how GEA works in practice ¿ the relationship of GEA with portfolio management and agile working ¿ the design of the enterprise architecture function and the measurement of its maturity ¿ how GEA can be combined with other tools, such as strategic governing tools, enterprise architecture methods and frameworks, and reference architectures This book is designed to enable the reader to 'do' GEA and to fit it into their daily architectural practice, with the aim of improving the performance of enterprises.