In Quantitative Risk Assessment (QRA), what is the ALARP principle?

In Quantitative Risk Assessment (QRA), the ALARP principle, which stands for "As Low As Reasonably Practicable," is the principle that the level of risk remaining after protective measures have been implemented should be reduced as much as reasonably practicable. This means that all reasonably practicable measures must be taken to reduce the risk, even if the cost of those measures is significant. The ALARP principle recognizes that it is often impossible or impractical to eliminate all risk completely, but that efforts should be made to reduce risk to a level that is tolerable. The determination of what is "reasonably practicable" involves balancing the cost of the risk reduction measures against the benefits they provide. This assessment considers factors such as the severity of the potential consequences, the likelihood of the event occurring, the cost of implementing the risk reduction measures, and the technical feasibility of those measures. If the cost of the risk reduction measures is grossly disproportionate to the benefits, then it may not be reasonably practicable to implement those measures. However, the burden of proof is on the organization to demonstrate that the cost is indeed grossly disproportionate. The ALARP principle ensures a structured and justifiable approach to risk management, striving for continuous improvement in safety performance. Therefore, reducing risk to a tolerable level while considering cost-benefit is the essence of the ALARP principle.