The reliability of engineering systems evolves over time and depends on random processes of loads and system properties. However, only a small portion of existing research in structural reliability analysis and rare event simulation addresses the time variant nature of reliability. This book addresses this gap with contributions from leading researchers, based on the Joint Committee on Structural Safety (JCSS) workshop on time-variant structural reliability analysis, held in December 2024 at the Technical University of Munich. The topics covered include analytical and simulation-based reliability methods, stochastic dynamics, surrogate modeling, sensitivity analysis, Bayesian updating using monitoring data, uncertainty quantification, non-stationary stochastic modeling under changing climatic conditions, and codified approaches for reliability-based design and assessment. The book not only offers a solid introduction to the fundamentals of time variant structural reliability theory but also provides a compendium of recent developments in the field. It serves both as a reference work for graduate students and as an accessible resource for researchers and practicing engineers.

Iason Papaioannou is Assistant Professor in the Department of Structural Engineering at the National Technical University of Athens (NTUA). His research focuses on structural reliability assessment, data-driven uncertainty quantification, uncertainty-based sensitivity analysis, Bayesian methods, and probabilistic machine learning. 

Oindrila Kanjilal is a postdoctoral researcher at the Technical University of Munich, working on computational methods for uncertainty quantification in engineering systems. Her research interests include structural reliability analysis, Bayesian updating, and reliability-based design optimization.

Jianbing Chen is Distinguished Professor at Tongji University in the College of Civil Engineering. His research focuses on nonlinear analysis of structures, uncertainty quantification, stochastic mechanics, structural reliability, and design optimization of engineering systems. He currently serves as Chairman of the Executive Board of the International Association for Structural Safety and Reliability, and the Co-Editor of Probabilistic Engineering Mechanics.

Daniel Straub is a Professor at the Technical University of Munich (TUM), specializing in risk and reliability analysis for engineering systems. His research focuses on probabilistic physics-based and data-driven models and methods for decision-making under uncertainty.