Many, perhaps all, registers I have seen include entries for “inherent risk” and “residual risk”. An attempt is made to ‘quantify’ the inherent and residual risk using (typically) the “Risk Matrix” variables of Likelihood and Consequence.
The post “The Risk Register” in support of Chapter 11 of Occupational Risk Control notes two problems with this practice:
- “the Risk Matrix is not actually capable of being used repeatably or objectively (There are peer-reviewed papers to support this contention). One aspect of this, of many, is that Risk is actually a relationship between Frequency and Consequence Value, not a single value in which “Likelihood” (which is a synonym of probability) replaces Frequency.
- “… it is not helpful as in no case in which a moral obligation exists (it is hard to find a Risk for which this is not the case) is a court interested in how big you thought the Risk was.” You only have to ask a lawyer familiar with such cases.
See https://www.derekviner.com/the-risk-register/
Nevertheless, what about these two terms themselves? Is there any logical meaning that may be given to them?
If a risk is logically and objectively described (see the post “Describing Risks” in support of Chapter 4 of Occupational Risk Control) the description consists of a suitably easy to read statement of the asset at risk, the essential nature of the process that threatens the asset and something of the situation within which the risk exists.
See https://www.derekviner.com/describing-risks/
Given this, so long as a threat exists to an asset, a Risk will exist. Either remove the asset or the threat and there is no risk. Is there anything about a Risk that is therefore ‘“inherent”?
This is the argument given in Chapter 7 of Occupational Risk Control:
The word inherent, meaning permanent and essential (Oxford English Dictionary), conveys the implication that nothing can be done to change the risk and so is an entirely inappropriate term to use for this purpose. Residual risk is simply the risk that remains after control measures have been put in place. As control measures are always in place, no matter how good or bad they are seen to be, all risk is residual at all times and there is no point in using the term.
So, to conclude in brief:
- The term inherent is not appropriate as an adjective applied to risk
- All risk is residual as all risks are under some form of control at all times
- Attaching Risk Matrix labels to the likelihood and consequence value of a risk no matter what adjective is attached to it is unreliable and irrelevant.