In human factors, we often talk about the importance of completing a task correctly—without use errors. However, an element of completing a task that is seldom talked about, yet quite important, is the time it takes to complete a task. If a user can administer medication using an injection device without use errors, but can only do so if they spend 30 minutes to an hour on the activity, that isn’t considered a success. Not only should users be able to complete tasks correctly, but they should be able to complete tasks efficiently.