This book covers enterprise architectures and integration using SOA principles. This book is based on corporate experience, consulting assignments, teaching university courses and also research on computer aided consulting. The salient features of this classroom tested book are: a) emphasis on recent and relevant issues; b) mixture of business and technologies, not just buiness or pure technology; c) a systematic approach that defines an enterprise architecture into broad building blocks and then covers each building block in depth; d) several case studies and examples to illustrate the key points; e) a step by step methodology that shows how all the pieces fit together; and f) a computer aided decision support system (PISA) that can be used in classroom exercises.