Every month, our vendor is required to report this total on the project as a whole and on key deliverables. I’m used to seeing the numbers reported and how to calculate them. I’m not asking for the Cost Performance Index (CPI). I want to know how far over or under we’re going to be compared to the budget.
The formula I memorized for the PMP exam and the same formula I use to calculate VAC today is: Variance At Completion = Budget At Completion – Estimate At Completion
(VAC = BAC – EAC)
So, I ask myself,  why is there no VAC definition and  VAC formula in the PMBoK?