Definition:
ALARP describes the principle that risk should be reduced to a level that is as low as reasonably practicable, balancing the time, trouble, and cost of further reduction against the benefit achieved.
The process of determining ALARP can be lengthy, but it often results in a final document such as the calibrated risk matrix.
Key Points:
- Central to risk management decisions in safety lifecycle activities.
- Tied to the definition of tolerable risk
- Additional risk reduction is not mandatory when it would be grossly disproportionate to the expected benefit.
- ALARA – as low as reasonably achievable is used in radiation space
- SFAIRP – so far as reasonable practical – similar term in the UK in medical space
Example:
Reducing a fatal accident risk from 1E-4 to 1E-5 per year could be considered not ALARP if it would require an impractical $10 million capital investment for only marginal risk benefit.
See also: calibrated risk matrix, tolerable risk
Cited Source:
- IEC 61511-1:2016, Clause 4.3.2.