Enterprise architecture is a key competency for most large organisations of the present day. Its roots reach back some twenty years or more, in early efforts to re-use knowledge about software structure and design to assist in managing a rapid growth in the cost and complexity of IT systems in general. Compliance to a formal enterprise archi-tecture framework is now mandatory in many government and defence contexts, and is increasingly common in larger organisations elsewhere. For most of its history, enterprise architecture has been regarded as belonging under IT governance. Yet at the present time the discipline is evolving once more, and extending its scope to become a literal architecture of the enterprise. This Pocket Guide describes the purpose, role and value of architecture in the enterprise, and the makeup and skillsets of the architecture team in different business contexts. It explores the relationship between architecture, project management, change-management and governance, and summarises the frameworks, methods, standards and toolsets currently in common use. And finally, it provides a brief outline of the typical activities and processes that are used in the development and realisation of an enterprise architecture.