Gaba analyzes why the health care industry performs as it does and discusses complementary theories of organizational safety in other high-hazard organizations, including aviation, nuclear power plants, and the military. He discusses the two predominant theories of organizational safety, normal accidents theory and high-reliability organization theory, as they apply to the complex world of health care and provides specific parallel examples in other industries. Gaba examines the past record and future potential of health care to set goals in patient safety, provide tools and conditions to achieve those goals, measure attainment of those goals, and take effective action if the goals are not being met.