The shorthand initials WIP represent one of the most beloved or reviled parts of being a writer. If you don't have a WIP, your writing is dead stagnant. If you do have one, your writing is alive and, hopefully, thriving. Without a WIP, you're free! You can do whatever you want! You can go out with your friends, read, go to movies, play with your dog, travel, and all without any guilt. When you have one, it can take over your life to a point when you frequently spend more time thinking about it than noticing what's happening in the world around you.
If you didn't already know this, WIP = Work in Progress. But what does that really mean? What actually constitutes a work in progress? Is it just drafting, or does it include reaching a certain word count goal in your draft before you can award it that WIP title? Can you still consider something in progress if it's been shelved for a number of months, or years? Is progress being made on something if you haven't written the first word?
I think it all depends on what you consider progress. In the teaching game, progress is everything. Students come at you with so many varying abilities, and what you want most for them is to see that, regardless of what starting point they showed up with on the first day, they're continually improving. This might mean huge leaps for some and gradual steps for others, but as long as they're making progress you know things are going in the right direction.
As for me, I consider a writing project an official Work in Progress as soon as I've decided to commit time to seeing it completed. The problem is, this means I've got several works in progress happening at any given time, and juggling them requires an extra layer of management to keep that progress going with any of them.
Right now I've got five projects I would consider being in the WIP rotation. One of them is in a holding pattern since there really isn't much else I can do with it at the moment, but that's likely to change, eventually. Another one is in the first position for my work time now, since I'm working through what I hope is one of the last revision passes for it. Two others are little more than gestating collections of notes, actively competing against each other to see which one will get to be drafted next when my current revision project is finished. And the fifth is mostly an idea at this point, but every time it crosses my mind it gets to be a little more real and a little more intriguing. These days I'm toying with the idea of making it my NaNoWriMo project for this year, just to see where it goes (provided my current revision work is making enough progress to allow me to pause for a month and take on NaNo again).
So, as you can see, there's quite a bit going on here. To say nothing of my day job.
Some writers struggle with waiting for the next idea to come along, while others can't decide which one is next up in line. If you're one of the people in that second group, this is a lucky problem to have, but it's still a problem nonetheless. Trying to write four or five different things at the same time could easily produce four or five marginal manuscripts instead of the one really good one that might have happened with more focused time management. I don't see anything wrong about working out several ideas at once. If you can make that work inside of your process, it might even prove to be a benefit. But I think it's important to remember not to spread yourself too thin. You can't always chase after the prettiest, newest ideas that come along just because they seem like more fun than the one you've already put so much time and energy into. If you have a project in front of you that you believe in and you want to bring to life, keep at it. Keep making that progress, no matter how gradual it might be. As long as something is happening with it, it's still alive, and it still gets to keep that WIP title.
Because the great thing about a WIP? That 'P' part means you can keep working on it right up until the day it stops being a "Work in Progress" and shifts over to "Writing is Published." Until that happens, you can do whatever you want with it, and work at whatever pace you need.