James Reason, the British psychologist whose Swiss cheese model formed the basis of many aviation accident analyses and accident-prevention efforts, has died. He was 86.
Reason’s Swiss cheese model of accident causation was widely used not only in aviation but also in medicine and other fields to develop procedures to prevent accidents and other undesired outcomes. In the Swiss cheese model, defenses against an accident are compared to slices of Swiss cheese, with the holes in each slice representing weaknesses in different parts of the system. A system failure occurs when holes in all slices line up, leaving no defense against an accident.
In his autobiography, Reason explained that his development of the Swiss cheese theory followed an incident in which he absent-mindedly spooned cat food into a teapot. His action was unintentional but also not random, as the cat had interrupted his tea preparations with a loud demand for food. The theory inspired by that incident …
