A group of programmers hard at work
Our help site serves hundreds of thousands of pages a month, and we know which content is good from ratings, comments, and other statistics. We fix what might not be working for our customers. Of course we try to get it right the first time, but we all know that perfection by deadline is impossible. So we do quality control, and we update, and there's really no such thing as writer's block or missing deadlines at work.
As Gigi mentioned, with fiction, the buckets of time given to any one work in progress are not fixed. I don't know any fiction writer* who sits down at the blank word processing file and says, "Okay, I've got 40 hours to outline, 160 hours to get the rough draft, 20 hours to up the stakes, 10 hours to fill in emotional color, 24 hours for sensory detail, and 1,000 hours to make it brilliant."
Because fiction doesn't work that way. It comes from both sides of a writer's brain. You can spend four, six, or eight hours a day writing, but one 45 minute session might net you three pages of your most brilliant work, while eight hours on a bad day might net you negative 600 words! And you can't just wait for the good days, you have to writer through the bad ones.
Hm, writers don't look so different from programmers on the outside!
Fiction is annoyingly non-modular. The basic building blocks of character, action, setting, theme, and premise are all wickedly intertwined and reinforcing. Character is action, or action is character, setting can become a character, and conflict can be revealed through dialog. White space, what you don't say, can illuminate what you are saying.
In software documentation, white space exists only to give our customers' eyes a rest, or a way to find the headlines. There's very little subtext in documentation.
As I struggle to really stop writing crime novel #1, and start #2 with full focus and concentration, I realize that some of my hesitation is simply that it doesn't ever feel done until a deadline is imposed. Or until you realize, as a wise friend once said, that you are simply rearranging deck chairs on the Titanic.
I'm ready for a new ship. Goodbye, crime novel #1, it's been fun! But the horizon is calling me, and I'm really tired of those damn deck chairs.
* I do know one writer who may do this, but it's a hangover from her technical writing days, if she does.