A scroll through these posts, which are the ones that mention Leveson will give an overview.
Deepwater Horizon incident is discussed.
A draft copy of Nancy Leveson’s book is available free on-line:
Traditional risk and failure analysis focuses on specific pathways that lead to accidents, identifying potential points of failure and the singular “causes” of the accident (most commonly including operator error). Leveson believes that this approach is no longer helpful. Instead she argues for what she calls a “new accident model” – a better and more comprehensive way of analyzing the possibilities of accident scenarios and the causes of actual accidents.