There is so much blather about Earned Value, I've run out of energy trying to provide corrections and switched to have other people do my work for me.
Here's a nice paper that surveys many of the reasons EV fails to fulfill it's promise.
The answers have nothing to do with Earned Value and everything to do with the competencies of the project, business, and technical management of the project or program.
The organization sponsoring the conference this paper is from has a nice library is important topics in cost, schedule, risk, and earned value management. Worth a read and a shortcut for reference.
