Probabilistic Risk Assessment (PRA)
A “top down” approach used to apportion risk to individual assets to achieve an overall target level or risk for a facility.

These levels of risk are then used in risk-based techniques, such as reliability-centred maintenance to assist the development of appropriate asset maintenance strategies, and to identify required asset modernization. 

In a PRA, risk is characterized by two quantities:

  1. the magnitude (severity) of the possible adverse consequence(s), and
  2. the likelihood (probability) of occurrence of each consequence.

See also: