Sometimes it takes longer to automate something than it would to just repeat it yourself. Calvin designing a robot to clean his room, for instance. The method of estimating how long it takes to do the thing, how many times you have to do the thing, and then how long it would take to automate doing the thing, is a pretty good guideline.
But there are other factors: Like, can you include it in a checklist? If not, what are the chances that you’ll forget to do the thing? And what happens if you forget? What if you might hand things over to someone else and three people down the line, the fact that you need to do the thing doesn’t get passed along?
Or what if you have a situation like Desmond at the Dharma Initiative numbers station, and they know the step is “required,” but don’t know why? (Not that you’re likely to have quite so severe a failure mode!)
Anyway, today I automated some post-processing on a site that I hardly ever change. Not because it’s a pain to do the post-processing. Not because it takes a long time. But simply because if I don’t build it into the process, the next time I change something a year down the line I’ll probably have forgotten that I need to do the post-processing!