Building Management Systems (BMS) have revolutionized the way we manage and operate buildings. As technology continues to advance, the capabilities and potential of BMS are expanding, offering new opportunities for energy optimization, occupant comfort, and sustainability. This book aims to provide a comprehensive understanding of BMS, from its fundamental principles to emerging trends and innovations. In this book, we delve into the intricacies of BMS, exploring its components, architecture, and functionalities. We discuss the interconnectedness of various building systems and the role of BMS in integrating and optimizing their performance. With a focus on energy management, we examine strategies for reducing energy consumption, integrating renewable energy sources, and participating in demand response programs. Maintenance and lifecycle management of BMS are essential considerations for ensuring its long-term effectiveness. We provide insights into preventive maintenance practices, software updates, and equipment replacement, enabling building managers to maintain optimal system performance and plan for the future. The integration of BMS with smart building technologies is a key topic of discussion. We explore the integration of IoT devices, data analytics, AI, and machine learning, and how they enhance automation, prediction, and real-time optimization within buildings. We also look at the future trends and innovations in BMS, including digital twins, edge computing, and sustainability practices, providing a glimpse into the exciting possibilities that lie ahead. Throughout this book, we aim to empower building owners, managers, and professionals in the field of facility management with the knowledge and tools to leverage the potential of BMS. We hope that by understanding the principles, functionalities, and future trends of BMS, readers will be able to optimize building performance, enhance occupant experiences, and contribute to a more sustainable future. It is our sincere hope that this book serves as a valuable resource for anyone interested in BMS, whether they are beginners seeking a foundational understanding or experienced professionals looking to stay updated with the latest industry advancements. We invite readers to embark on this journey with us as we explore the world of Building Management Systems and unlock the potential for smarter, more efficient, and sustainable buildings. Charles Nehme