This book provides the concepts and methodologies of probabilistic structural performance assessments and predictions for deteriorating structures, with emphasis on marine structures and special consideration of system reliability, risk, longevity, sustainability, and optimal decision making. It introduces a comprehensive framework for time-dependent structural performance analysis, incorporating maintenance strategies to estimate and/or extend service life of infrastructure systems. The integration of structural health monitoring highlights the pivotal role of data analytics in addressing uncertainties and optimizing service life management. Progressing from foundational theories to advanced optimization strategies for inspection, monitoring, and maintenance planning. This book, which is a valuable resource for students, engineers, researchers, decision-makers, and policymakers, critically addresses economic considerations through cost-benefit utility and information analysis. Additionally, the exploration of multi-objective optimization and optimal decision-making processes presents the intricate trade-offs involved in the stewardship of marine and civil infrastructure.