This book is a comprehensive guide to the classification, design, construction, and maintenance of subsea pipeline systems. It provides an in-depth exploration of offshore pipeline architecture, serviceability, and the rigorous standards required for certification and verification. The chapters cover critical topics such as risk evaluations for novel features, survey and inspection regimes, materials and welding specifications, geotechnical and environmental conditions, flow assurance analysis, strength and stability criteria, and special considerations for pipe-in-pipe designs. Readers will also discover detailed discussions on pipeline rectification, intervention design, routing, installation procedures, testing protocols, and maintenance strategies. This book is an indispensable resource for anyone involved in the offshore oil and gas industry. Engineers, architects, and safety management professionals will find this book particularly valuable. It serves as both a reference for academics and students in industrial design and engineering fields and as a textbook for marine architecture courses. Whether you are overseeing the design of new pipelines or ensuring the integrity of existing ones, this guide offers the latest research and practical insights to help you navigate the complexities of subsea pipeline systems.