I suspect it's going to be like any other contract writing--how you get it done on time, of adequate quality, depends on how you work best.
Speaking for myself, if I had a Big Picture idea in place or assigned, and I committed to two two-hour writing sessions a day with no distractions (none!), I'd finish a 65,000 word erotica novel in plenty of time.
Of course, you may not work best that way. Maybe you need to outline and do character sketches and setting research before you write. Or maybe you need to establish a number of words or pages you must write per day, or per week. Or maybe you're like one writer I know who does her very best work under pressure and starts quite late in the game, works like a madwoman for a short time (sacrificing friendship, family, normal food, hygiene, and most of her other responsibilities) and turns in something decent, on time.
Let us know if there's any way we can support you!
Maryn
