^Actually, I've heard it from a writer called Tais Teng It's one of my favourites, together with the milestone-and-deadline system I've created together with my husband.
I've experienced repeatedly that I procrastinate on the writing (maybe a little bit fear of failure, probably mostly the perceiver's weakness) and I'm frustrated of lost time in which I could have written.
Husband: "Don't tell me you want a deadline on your writing!"
Me: "Actually that could work. Let's try one."
Husband (half joking): "Okay, by next Wednesday you make a list of things you want to do and an estimate on how long each should take."
Next Wednesday I had not only made the list, I actually had already crossed several items on it! Just by writing down I needed to eg. "make Main character discover Sidekick is in love with her" my subconscious started to work on it and after a day or two I actually had a novel-worthy scene.
Then my husband told me which items to finish in two week's time. In most of the occasions I met the milestone; sometimes I overshot; sometimes I finished other items than the ones appointed, and on a few occasions I didn't meet it.
I've created three quarters of the novel in more than two years. The last quarter, together with the overall revision and non-creative but necessary things like "check timeline" and "check appearance characters" and a style (*), spelling and grammar scrutinizing, took me four months (which were interrupted by exams and family holidays).
Now I'm writing a new one, and I want to begin the milestone system as early as possible. A little outside stress makes me a hell of a lot more productive. It took me two months to work out the idea and a few scenes and dialogue to the point I was able to make an outline with estimates. Now, two weeks later, I have written +/- a quarter of the book, met my very first milestone of this one. I'm totally happy with the system.
(*) Style: a time-consuming but nevertheless very efficient method is reading out loud. Not "loud in your head" but really loud. It takes a lot of time to go through your work like this, but the improvement on style is astonishing and you only need to do it once.