This Handbook is about methods, tools and examples of how to architect an enterprise through considering all life cycle aspects of Enterprise Entities (such as individual enterprises, enterprise networks, virtual enterprises, projects and other complex systems including a mixture of automated and human processes). The book is based on ISO15704:2000, or the GERAM Framework (Generalised Enterprise Reference Architecture and Methodology) that generalises the requirements of Enterprise Reference Architectures. Various Architecture Frameworks (PERA, CIMOSA, Grai-GIM, Zachman, C4ISR/DoDAF) are shown in light of GERAM to allow a deeper understanding of their contributions and therefore their correct and knowledgeable use. The handbook addresses a wide variety of audience, and covers methods and tools necessary to design or redesign enterprises, as well as to structure the implementation into manageable projects.