Discovery and Problem AnalysisResource

Fault Tree Analysis

Tracing the causes of an undesirable event.

Fault tree analysis starts with an undesirable event and works backwards through logical combinations of possible causes. It identifies failure paths and where preventive controls may be required.

How to use this tool

  1. Define the top event

    Define the unwanted top event.

  2. Work backwards with logic

    Work backwards using AND and OR logic.

  3. Break down to specific causes

    Continue until the causes are specific enough to investigate.

  4. Prioritise preventive controls

    Validate the causes and prioritise preventive controls.

References & further reading

Vesely, W. E. et al. (1981). Fault Tree Handbook. U.S. Nuclear Regulatory Commission, NUREG-0492.