This chart illustrates the original application of the Swiss Cheese metaphor to describe operational failures.

Cumulative defenses

Accidents in complex system occur through the accumulation of multiple factors and failures. The Swiss Cheese Metaphor suggests that incidences are due to penetration of events through defenses, represented by cheese slices. The traditional representation, commonly attributed  to Reason (Eurocontrol, 2006, download ), describes the propagation from hazard to incidence through defense layers.

Defenses are not perfect. The hazard evolves to incidence by passing through holes in the defense layers. Protection is best when there are many layers ( PL ...) , with only little holes.

This metaphor is used here to model the defenses incorporated in the resilience model ...,

 


Updated on 29 Nov 2016.