The author discusses concepts of human error, contrasting the person approach with a system approach in understanding the differing philosophies of error management. The person approach focuses on blaming individuals, whereas the system approach concentrates on the conditions under which individuals work. The author further explains several background concepts, including the “Swiss cheese” model of system accidents, the components of error management, and the principles of becoming a high-reliability organization. He explains the benefits of making the transition from a person approach to a system approach in the context of a high-reliability organization. This article is from a British Medical Journal special issue on patient safety.