A safety model is a set of beliefs or hypotheses (often implicit) about the features and conditions that contribute to the safety of a system. An accident model is a set of beliefs on the way in which accidents and incidents occur in a system and the causal factors that make them possible. The ental models concerning safety are important because they impact system design, operational decisions and behaviours.
We analyze a few accident models and safety models to understand the implicit assumptions underlying the models:
- H. Heinrich’s domino model of accident causation
- H. Heinrich’s and F. Bird’s safety triangle, the companion safety model
- epidemiological accident models such as J. Reason’s famous Swiss cheese model
- the bow-tie model of accident causation and the role of barriers
- a loss of control safety model
- J. Rasmussen’s drift into failure model
This submodule is a part of the hazard analysis module.
Safety models and accident models
Assessing risk controls using bow-ties