This book aims to provide a systematic approach to the design, assessment, operation, and maintenance of safety barriers that are used for preventing accidents and protecting humans, equipment, and the environment. Barrier Engineering: Models and Methods for Technical Safety is based on the philosophy of risk management, providing a thorough guide on identifying, analyzing, designing, operating, and maintaining safety barriers. It presents general theories, models, and both qualitative and quantitative analysis approaches, addressing both design and operational challenges for technical and non-technical barriers. The focus is on analyzing and evaluating the effectiveness and performance of technical safety barriers to ensure the functional safety of complex systems. This book also introduces the concepts of barrier security, applications of artificial intelligence, resilience, and sustainability considerations in safety barrier engineering and management. PowerPoint slides and a solutions manual are available for facilitating teaching and self-learning. This book can be used as a textbook for master-level students in process and machinery safety, industrial and systems engineering, and management, and it is also an invaluable reference for risk analysts and engineers in complex system design, operation, and maintenance.