Human error or use error…Make the switch!

FMEAs (Failure Modes and Effects Analysis) are a common tool used in industry by device manufacturers to help members of R&D think of risk mitigation strategies to embed within their process whilst they are in the product development stages. FMEAs traditionally focus on system/component failures that can affect the operation of a device whilst UFMEAs (User Failures Modes and Effects Analysis) are intended to help members of R&D to focus on use-related errors. The term ‘Use Error’ has recently been introduced to replace the commonly used terms ‘Human Error’ and ‘User Error’, after the need to change the term was prompted by a high number of manufacturers commonly attributing errors to the users as opposed to investing in fixing error-prone device design.

Over the last few months we have seen several presentations and articles still referring to and attributing ‘Human Error’ to the poor usability of devices. However the term ‘Human Error’ or ‘User Error’ insinuates that the fault lies with the user for using the device incorrectly rather than with the design of the device causing the user to use it incorrectly. ‘Use Error’ refers to using a device in a way that is not intended by the device manufacturer. It refers to a mismatch between user input (which includes cognition and environmental factors) and the device they are using. In other words it refers to a mismatch between how users think, perceive, rationalise, learn and understand which affects how they interact with a device. When conducting use-related risk analyses people often struggle to focus on what a ‘Use Error’ actually is.

Arguably in some instances, errors may actually be caused by a user due to either a momentary lapse in memory or a simple mistake caused by an exceptional circumstance. But how do you handle this type of error? This is a common question which often pops-up when discussing use-related errors. How can you possibly cover off every mistake a user might make, no matter how weird and wonderful it may be? The answer is you can’t (or maybe you could with great difficulty and a year of brainstorming use scenarios!). Trying to measure the multitude of possible mistakes users can make will not only drive you mad but, also in terms of likelihood of occurrence, most of them will rate very low. When thinking about ‘Use Errors’ you need to know where to draw that line. There are a number of things you can do to help decide on how to do this. Firstly you should look at the level of severity. Think about all of the tasks users need to perform in order to use a device and select those tasks which result in a higher severity if the device is used incorrectly. Secondly, do not think of all the weird and wonderful things a user might do (abnormal use), think about the errors you can foresee them making (reasonable foreseeable misuse) with the device that you are evaluating. These lessons are often hard to embed in our thinking because, as Humans, we have by nature a tendency to think of the worst possible outcomes that can affect us. By switching from the term ‘Human Error’ to ‘Use Error’ you start to remove some of this unwanted thinking and start to get people thinking more about the device and to consider the important issues users have with their devices that could potentially be designed out. This is the key change in thinking needed to be able to effectively conduct use-related risk analyses.

Users interact with devices in many different ways and their actions can be influenced by numerous factors such as their experience with similar devices, the intuitiveness of a device, the quality of training given to them, the clarity of instructions or their professional expertise and knowledge. By switching from the term ‘Human Error’ to ‘Use Error’ and by getting stakeholders within R&D (Management, Engineers, Designers and Testers) to understand and be empathic with their target end users’ challenges/needs whilst effectively considering use-related errors, manufacturers will be better equipped to design products and services which not only have a benefit to the user but can also add a competitive advantage over similar devices in the market.