Scheduler
The project scheduler, much like the project coordinator, is usually found in larger organizations and on long-term projects. But I can tell you: if I'm managing a project and a scheduler shows up, be prepared to see my happy dance! That is because the scheduler is doing exactly what it sounds like they're doing. They are developing and updating the project schedule, keeping track of schedule performance, and communicating schedule performance. In Chapter 6, Creating a Project Schedule, we will cover the process by which you define your tasks, sequence activities, estimate resources and durations, and then get a schedule approved as a baseline.
For myself personally, I find scheduling to be the most stressful aspect of project management. It's not that I can't do it, it's just that it stresses me out! Still others love scheduling and are very good at it, so I prefer to leave it to them, hence the happy dance.