It seems foolish when you think about it, but why would anyone keep the same amount of processes for a large project when performing a small project? This article from PM Foundations argues that processes should be scaled for the project at hand. Much as you wouldn't have 20 people working on a 3 person job, it simply doesn't make sense to have project management processes for a yearlong project when the project to be completed is only going to last a month.
To help decide just how much project management you should use on your next project, the article provides a few graphs showing where you might have too many (or too few) processes in place, what key processes should always exist, and how to determine where you currently sit on the scale. One of the more important lessons mentioned is making sure you document what processes worked and which were difficult, allowing for future projects to be even more “right sized” in project management.