Evolution of System Safety contains papers presented at the twenty-sixth annual Safety-critical Systems Symposium, held in York, UK, in February 2018. The Symposium is for engineers, managers and academics in the field of system safety, across all industry sectors, so the papers making up this volume offer wide coverage of current safety topics, and a blend of academic research and industrial experience. They include both recent developments in the field and discussion of open issues and questions. The topics covered in this volume include: Autonomy, AI and Machine Learning, Safety Services, Improving Practice, Human Factors and Safety Culture, Risk Analysis and Assessment, Security Informed Safety, Data Safety and Agile Development. This book will be of interest to practitioners, managers and academics working in the safety-critical and safety-related systems areas.