Decision making related to the safety of complex technologies is difficult in the best of circumstances. In the face of significant uncertainty, decision makers rely on input from a variety of sources, including the results of system safety analyses. System safety is a widely accepted management and engineering approach to identify, analyze, and address risks in complex systems such as chemical processing plants, nuclear power plants, railroads, airplanes, and rockets. When used correctly, system safety methods can provide tremendous benefits, focusing resources to reduce risk and improve safety. But for a variety of reasons system safety analyses may fail to identify hazards, assess risks, implement safeguards properly, or verify that risks have been reduced. A decision maker must be able to differentiate between effective and poor system safety efforts in order to make critical safety decisions. One of the best tools available to a safety decision maker is asking intelligent questions to try to understand whether the system safety approach used truly reduces risks. Essential Questions in System Safety provides probing questions that should be asked by any organization building and operating complex systems. These questions should serve as a springboard to additional inquiries and evaluations by safety decision makers. The questions provided here may be used with the companion book The System Safety Skeptic: Lessons Learned in Safety Management and Engineering to help improve the safety of complex processes and systems.

In making safety risk decisions, decision makers rely on input from a variety of sources, including the results of system safety analyses. System safety is an accepted management and engineering approach to identify, analyze, and address risks in complex systems such as chemical processing plants, nuclear power plants, railroads, airplanes, and rockets. When used correctly, system safety methods provide tremendous benefits, focusing resources to reduce risk and improve safety. But for a variety of reasons system safety analyses may fail to properly identify hazards and assess risks. A decision maker must be able to differentiate between effective and poor system safety efforts when making critical safety decisions. Safety decision makers must be able to ask intelligent questions to determine whether the system safety approach used truly reduces risk. However, without extensive knowledge in system safety, a decision maker may not know what questions to ask. Essential Questions in System Safety was developed to address this gap. This book is intended to be a guide to safety decision makers, filled with probing questions, including a chapter focused on software and computing systems. The information provided should help decision makers assess risks associated with building and operating complex systems. The reader should use these questions as a starting point and a springboard to additional inquiries and evaluations to improve the safety of complex processes and systems. Although Essential Questions in System Safety stands on its own, it also serves as a companion to the book The System Safety Skeptic: Lessons Learned in Safety Management and Engineering, which details the system safety process and provides numerous lessons learned in safety management and engineering.

Terry Hardy has provided engineering, assurance, and risk management support to multiple commercial and government organizations, and has served in leadership roles in safety, reliability, and quality assurance at the National Aeronautics and Space Administration, the Federal Aviation Administration, and the U.S. Consumer Product Safety Commission. He is the author of numerous safety and engineering publications, and has led many efforts to develop risk management regulations, guidance, and training.