This book is about how safety analysis can be practically applied as a tool for accident prevention. The main focus is on qualitative methods, which can be used to analyse systems and to investigate accidents. The book presents more than 40 methods, including techniques for risk evaluation, such as the Risk Matrix. The emphasis is on general methods that can be applied in various contexts, such as industry, production, transport, medicine, and public events. The planning section discusses the practical aspects of a safety analysis, such as defining its aims and specifying the types of results desired. It also considers arguments for and against specific methods. The examples section presents case studies of accident investigations, and of analyses of systems in different settings. Lars Harms-Ringdahl has been engaged in safety as a researcher, consultant and teacher for many years. He works at the Institute for Risk Management and Safety Analysis in Stockholm, and has been professor at the Royal Institute of Technology, Stockholm, and at Karlstad University, Sweden.