BAC (Budget at Completion)

What the number is

BAC (Budget at Completion) is the total approved budget for all project work. Accumulate planned value (PV) to the end of the project and the final figure equals BAC. On a project budgeted at $1M, BAC is $1M, and the PV curve — the planned line of the S-curve — climbs toward that value and touches it at completion. Unlike the other EVM figures, BAC is not a measurement; it is a constant of the approved baseline.

Why it matters

Every EVM forecast formula anchors on it. Estimate at Completion, EAC = BAC ÷ CPI; the canonical Estimate to Complete, ETC = (BAC − EV) ÷ CPI; Variance at Completion, VAC = BAC − EAC; and the To-Complete Performance Index, TCPI = (BAC − EV) ÷ (BAC − AC). "What we agreed to finish for" sits in the denominator or the reference point of each. If BAC moves, every one of these indicators moves with it — which is why changing BAC belongs to change control, not to re-estimation.

Common misconceptions

BAC is easily confused with the spending cap approved so far, or with the contract price. It is the total budget assigned to the performance measurement baseline (PMB): management reserve normally sits outside BAC, and contract profit is not part of it. And quietly raising BAC when progress lags makes CPI and VAC look better without anything improving — moving the baseline constant to flatter performance is not measurement, it is window dressing.