1. What is a bow tie?

1.1 Principle

The principle of the bow-tie method is to bring together a fault tree and an event tree centered on the same feared event.

The part upstream of the dreaded event consists of a fault tree, which makes it possible to analyze the combinations of causes and highlight the effect of prevention barriers on the accidental sequences leading to the occurrence of the dreaded event.

The downstream part consists of an event tree. It is used to determine the nature and extent of the consequences, depending on whether or not the mitigation barriers are fulfilling their...