One of my courses is new this semester, so despite all the advice that people have been getting (see Profacero's post, for example, or the comments in the Another Damned Notorious Writing Group threads) about not spending any time on course prep but saving time for writing, unless you want to go into a classroom with egg on your face, you have to do something.
This is the reason for spending a writing day the other day dreaming up assignments and exercises for this and the other courses. The downside: losing a day of writing. The upside: now these things are done, and I don't plan to revisit them. If you've taught for years, you know what works and what doesn't, and if you make a mistake and write a bad part of an assignment, you adjust your expectations and fix it the next time.
What keeps me going, though, is the back-of-the-mind metaphor that now that I've done this course once, I never have to do it again. It's in the bank, so to speak. Realistically, a course is never really done; you think of what could be done differently or better the next time you teach it. Still, you don't have to invent every single thing from scratch, the way you do with a new course, and it's unlikely that you'll need to (although I would) share materials with others who teach the course in later semesters. It becomes your course, and you are identified with it--for this moment, anyway--whether it succeeds or it doesn't.
In an online course, you're still working with a banking model, but the push from higher-ups is different. In effect, if the course has been taught by someone else before, there's a strong pressure for you not to change anything--assignments, readings, syllabus--and to use what has been done before. Instead of making deposits, you're supposed to withdraw from the account that someone else has established.
Now, in theory, this would be a huge timesaver, since you don't have to put all that time into creating new assignments and could spend it on writing. But if you are stubbornly perverse about teaching your own material, as I am, and if you see ways to improve the course, as I did, you ignore the pressure and design the course the way you want it. The difference is that this time, you're banking the course not on your own computer but on the university's server, and if you don't keep extra copies of the materials on your own computer, all your work could be lost if everyone else doesn't want to teach your course the way you designed it (and why should they?). You've banked it, but you don't own it. If it stays, it's not really associated with you as a teacher, and it can disappear.
We don't really "own" courses, of course, and all that banking imagery just makes the loss of time for other work easier to justify. It's just a different feeling. In one, I'm putting aside material that I can draw on later, and it has my name on it. In the other, I'm developing material anonymously for a collective pool of materials. Both have their advantages, but I'm struck by how different they seem.