Build the event tree
The event tree: a risk analysis method

A tree is built using inductive reasoning which, for each of the safety barriers put in place to reduce the intensity of the consequences, allows two cases to be studied:

• The barrier fulfils its safety function.

• The barrier does not fulfil its safety function.

In other words, for each of the mitigation barriers implemented, the following two questions must be answered:

• What happens when the barrier "works"?

• What happens when the barrier "doesn't work"?

An example of an event tree is shown in the figure "Structure of an event tree". In this theoretical example, two safety barriers are considered to limit the consequences of the initiating...