Safety III: A systems approach to safety and resilience (7 January 2020)

Summary

Recently, there has been a lot of interest in some ideas proposed by Prof. Erik Hollnagel and labeled as “Safety-II” and argued to be the basis for achieving system resilience. He contrasts Safety-II to what he describes as Safety-I, which he claims to be what engineers do now to prevent accidents. What he describes as Safety-I, however, has very little or no resemblance to what is done today or to what has been done in safety engineering for at least 70 years.

In this paper, Prof. Nancy Leveson, Aeronautics and Astronautics Dept., MIT, describes the history of safety engineering, provides a description of safety engineering as actually practiced in different industries, shows the flaws and inaccuracies in Prof. Hollnagel’s arguments and the flaws in the Safety-II concept, and suggests that a systems approach (Safety-III) is a way forward for the future.