Eliminating every single risk in a complex operation is impossible, in fact even in simple projects you can never predict or eliminate all risks. This means that you must accept a certain level of risk. 

Determining whether a risk is acceptable or not can be difficult though. A lot of factors can affect perception of a given risk. Using the ALARP-principle can be helpful when deciding if risks need acting upon. 

Understanding the ALARP-principle 

The ALARP-principle is in its core, a way of thinking that compares a risk with the resources required to reduce that risk, whether it be monetary costs, time requirements, troubles incurred or loss of production trying to reduce this risk any further. ALARP is an abbreviation of As Low as Reasonably Practicable. It is usually accompanied by an illustration of an inverted triangle with 2 horizontal lines going through it.

The 2 horizontal lines function as boundaries where a risk will be defined as either ‘Unacceptable’, ‘Acceptable’ or ‘Generally acceptable’. The middle area, also known as the ‘ALARP region’, is the focus of this article.  

If the cost of lowering a risk is greater than the increase in safety, and that risk generally is deemed acceptable, it belongs in the ALARP-region. This means, that the ALARP-principle is a way of thinking, where the risk is held up against cost of reducing said risk. Even though a risk is within the ALARP-region from the get-go, it is still important to consider if it is worth introducing additional risk reduction measures to move it further down the triangle. 

Implementing the ALARP-principle 

To use this principle, it is important that you already have a general idea of your risks and the scope of these. With this knowledge, it is possible to plug the risks into the model – thus creating a visual product, where the risks can be ranked based on your assessment of them. 

The ALARP-principle also works well with a risk matrix, where the colour-coding can help visualizing what is deemed an acceptable risk and what isn’t. ALARP allows for flexibility in the decision-making process and allows for the organisation to set goals for duty-holder. 

Process when applying ALARP 

1. Quantitative assessment of total risk and assessment of hazard-source. 

• Begin by doing quantitative assessment of total risk regarding an activity or situation. 
• Evaluate each specific source of hazard contributing to the overall risk of the activity/situation. 

2. Measuring against the highest acceptable level of risk 

• Compare total risk with highest acceptable risk. 
• If the total risk is higher than highest acceptable level of risk, the activity must be put on hold until reduction measures have reduced risk to a level of acceptable risk. 

3. ALARP-region 

• If total risk comes out between highest acceptable risk and generally acceptable risk (which is the ALARP-region) the process can be allowed to proceed. 
• Even within ALARP-region it is still prudent to consider implementing more risk reduction measures. Especially if the risk starts out within this range. 

4. Generally acceptable risk or beneath this level. 

• If total risk is withing this range, you can continue. 

5. Additional risk reduction measures 

• In this step you need to identify additional risk reduction measures, both physical and/or operational measures. 

6. Reasonably practicable 

• Asses each risk reduction measure to determine whether it/they are reasonably practicable. You need to consider cost, time and ease of implementation. 

Sources: 

• Arbejdstilsynet, offshore.at.dk (https://offshore.at.dk/en/regulations/wea-guidelines/alarp-principle/). 
• Njå, O. et al. (2020). Samfunnssikkerhet – Analyse, styring og evaluering.