by Liz Mauer, MHCI
This is the fifth in a multipart series about how to effectively identify, understand, and communicate a product’s use-related risks.
URRAs can be useful tools to help proactively manage use-related risk. Most URRAs have a set of use-related risks and associated harms that range from negligible to serious. Manufacturers can prioritize design and development efforts on areas of the user interface that are related to the most serious harms, before they turn up as issues during a human factors validation test.
However, there are some products that have a URRA that contains mostly serious harms. When this happens, the URRA can lose its ability to help prioritize design and development efforts. We see this most often with emergency-use products (i.e., defibrillators, products that deliver epinephrine or naloxone, etc.). As an example, consider an auto-injector that delivers epinephrine. Most of the use errors for this product could result in various hazardous situations, such as no dose, partial dose, overdose, delayed dose, etc. Any of these could result in a harm of anaphylactic shock and/or death, and the severity for each use-related risk will end up (rightly so) classified as serious. When everything is serious and could result in death, what should you focus on for mitigations? Not to mention that at first glance, your product appears to harm people very seriously, when in fact it really is the opposite – your product is the very thing that could save them from such a catastrophic outcome. The optics of that never seem right to us.
There is a way to make your URRA useful again if you view your URRA through a different lens. By tying the resultant harm to the severity, you risk missing the differences in the underlying hazardous situations that could help you prioritize your design and development efforts for mitigations. That’s why for these kinds of products, we find it more helpful to tie the hazardous situation to the severity, instead of the harm. These are usually things like “no therapy,” “delay of therapy,” “partial dose,” “overdose,” etc. For those versed in ISO 14971, this is similar to the concept of P1 and P2 – the likelihood that a hazardous situation will arise (P1), and the likelihood of that hazardous situation leading to harm if it did (P2).
So set aside the worst thing that could happen (P2), and think about P1 instead – what could lead to these various hazardous situations? What could happen that leads to no therapy? A partial dose? And so on. Now you will have some daylight between these use-related risks that you can use to prioritize, and as an added bonus, your URRA will better reflect your product’s true use-related risk profile.