We use TriStar, Datafrond and Fishbowl, but really, no one actually understands how the whole thing works, and most places understand business requirements even less.
You end up having to thuroughly define your business requirements and use one or more consultants to make Windchill do what you want. Don't rely on PTC or 3rd parties to help you define your processes.
We've hacked our way through it, and put an incredible amount of time and a sickening amount of money; we still aren't where we want to be, but we're slowly creeping toward it. At least now we have no data loss.
You'll also find that Winchill requires customization to do the most basic PLM tasks like mass rollup, aging reports, etc.
Good luck.
