Frank Chips In
I'm sure that by now you have sorted it all out …
The problem lies in the meaning of PV. One can have PV at end of contract, or PV at any point during the project.
EV = PV (at end of contract) x %Com
SV = EV - PV (at the point in time that the EV was taken).
By the way, what sort of project are you using EV for?
I'm a bit of a heretic. I use the concept all the time, but seldom calculate the numbers
-- too much uncertainty for the types of IT projects that I run.
Let me know if you want to discuss it further …