In the context of Safety Management, “risky” industries such as Rail typically apply Risk Management analysis based on the approaches of As Low As Reasonably Practicable (ALARP) or So Far As Is Reasonably Practicable (SFAIRP). There may be significant differences in the outcome of your risk analysis, depending on which approach is applied.


Contrary to what you might expect, I’m not going to begin this article with a caveat along the lines of “this information does not constitute legal advice whether express or implied…..” It should be clear to the reader that I am approaching this subject from 50,000 feet in the interests of increasing general knowledge, awareness and curiosity around this important subject. Accordingly, if you are an interested reader you should make your own independent inquires, starting with the references included in this article (and perhaps send some feedback to the author as well?)


In the context of Safety Management, “risky” industries such as Rail typically develop risk assessments based on the approaches of As Low As Reasonably Practicable (ALARP) or So Far As Is Reasonably Practicable (SFAIRP). As Richard Robinson argues in his article “Near Enough Not Safe Enough” in the January 2014 edition of Engineers Australia (let me know if you would like further extracts from this article for personal purposes) there is a clear difference between these approaches. It is very important to be clear about this difference and the implications for risk assessments and associated management systems for Transport and Construction businesses.


The ALARP (As Low As Reasonably Practicable) approach recognises one of the fundamental principles of risk management: Risk cannot be completely eliminated and indeed, the pursuit of risk elimination will at some point not make sense from a cost – benefit perspective.

The ALARP point – the trade-off between resources and risk – is illustrated in the diagram below. ALARP is the level of risk that is tolerable and cannot be reduced further without expenditure disproportionate to the benefit gained or where the solution is impractical to implement.



ALARP Diagram, with acknowledgement to Julian Talbot of Jakeman Business Solutions


The definition of ALARP is drawn from a legal case heard by Lord Justice Asquith (Edwards v National Coal Board, 1949). Asquith said:


“Reasonably practicable is a narrower term than ‘physically possible’ and seems to me to imply that a computation must be made by the owner, in which the quantum of risk is placed on one scale and the sacrifice involved in the measures necessary for averting the risk (whether in money, time or trouble) is placed in the other; and that if it be shown that there is a gross disproportion between them — the risk being insignificant in relation to the sacrifice — the defendants discharge the onus on them.”


Using this definition, any Risk Management Plan must demonstrate that any additional “costs” (time, money, resources, etc) that are required to reduce the risk of the business venture further would be grossly disproportionate to the risk reduction being made.


In exploring the definition of “So Far As Is Reasonably Practicable” (SFAIRP) it is useful to refer to the Office of the National Rail Safety Regulator (ONRSR) Guideline: “Meaning of Duty to Ensure Safety So Far As Is Reasonably Practicable”.


This Guideline refers to Section 46 of the Rail Safety National Legislation (RSNL), under which duty holders are required:
a)      to eliminate risks to safety so far as is reasonably practicable; and
b)      if it is not reasonably practicable to eliminate risks to safety, to minimise those risks so far as is reasonably practicable.


The concept of SFAIRP is to achieve the best possible safety outcomes, to the extent that is “reasonably practicable”.
It is also common in the rail industry for the term As Low As Reasonably Practicable (ALARP) to be used. Both ALARP and SFAIRP have at their core the concept of “reasonably practicable”. The ONRSR considers that duties to ensure safety SFAIRP and duties to reduce risks ALARP call for the same tests to be applied. However, SFAIRP and ALARP are not always interchangeable because legal proceedings will have to employ the particular term cited in the relevant legislation.

This implies that there is a difference between applying SFAIRP and ALARP. So what is the difference???

The critical issue is that whilst both approaches set out to achieve the same outcome, SFAIRP explicitly take into consideration what are the available practicable precautions and then tests which are reasonable based on the common-law balance (of the significance of the risk versus the effort required to reduce it). The overall risk in a given situation may be at the ALARP level, and yet an untreated risk may remain that can be mitigated without disproportionate effort. As Richard Robinson emphasises: “…it does not matter how low the risk estimate is, if more can be done for very little effort, then the failure to do so will be negligent in the event of an incident.

The key to resolving this apparent dilemma lies in focusing on the term “reasonably practicable”. We refer again to Section 47 of the RSNL in which “reasonably practicable” is defined as that which is, or was at a particular time, reasonably able to be done to ensure safety, taking into account and weighing up all relevant matters including:

a)      the likelihood of the hazard or the risk concerned occurring
b)      the degree of harm that might result from the hazard or the risk
c)      what the person concerned knows, or ought reasonably to know, about the hazard or risk, and ways of eliminating or minimising the risk
d)      the availability and suitability of ways to eliminate or minimise the risk, and
e)      after assessing the extent of the risk and the available ways of eliminating or minimising the risk, the cost associated with available ways of eliminating or minimising the risk, including whether the cost is grossly disproportionate to the risk.


As the Guideline summarises: “There are no guarantees that a court will agree with a duty holder’s determination of what is or was ‘reasonably practicable’ in a given situation, however, it is far more probable the court will agree with the duty holder’s determination of what is or was ‘reasonably practicable’ if a process of justified decision making is adhered to.” Very important advice for those responsible for carrying out risk assessments.


Has this article been helpful? Please comment below or send me an email. I am always excited to hear from people making it happen!

Peter Wilkinson

BE (Mech), MBA