i've been doing it for a while, and well to me it worked. I didnt follow an official course just used tips around the internet. I was able to read a huge work related projected, and make the decision to go into it for our company or not. By speed reading i found the problems in the project a 500 page doc. And those where tackled by contract makers. later so it depends if you can do it or not, but dont put money in it