Book excerpt: The systems thinking philosophy has become popular in human factors and ergonomics and safety science. These methods are being used to understand and resolve complex societal problems in areas such as transport safety, workplace safety, medication error, disaster management, child abuse, financial crises, terrorism, climate change and public health and wellbeing. This handbook presents practical step-by-step guidance for practitioners and researchers wishing to use these methods to tackle complex problems. Each method includes an example case study which demonstrates how the method can be applied and how the results can be interpreted and translated into practical recommendations. The book presents practical guidance on state-of-the-art systems thinking methods and offers case study applications describing systems thinking methods in novel areas. It explains how to translate the outputs of systems thinking methods in practice and introduces systems thinking with an overview of Human Factors and Ergonomics applications. This book will serve as a great reference for students and engineers in the field of systems engineering, complex systems and the design and development of systems, including ergonomics/human factors and systems engineers, designers, architects, industrial engineers, project management engineers, reliability engineers, risk engineers, software engineers and computer engineers.