PV = 20,000. EV = 16,000. AC = 18,000. What is SPI, rounded to two decimals?
Rep 1 · by hand
Formula lab
The story tells you which formula. A calculator on exam day does not tell you which one.
Sheet
Cost variance
CV = EV − AC
Positive means under budget.
Schedule variance
SV = EV − PV
Positive means ahead of the planned-value schedule.
Cost performance index
CPI = EV / AC
Above 1 means under budget.
Schedule performance index
SPI = EV / PV
Above 1 means ahead on earned value. It is not a critical-path test.
EAC, performance continues
EAC = BAC / CPI
Use when the story says current variances will continue.
EAC, future back on plan
EAC = AC + (BAC − EV)
Use when past cost trouble was atypical.
Estimate to complete
ETC = EAC − AC
What you still expect to spend.
Variance at completion
VAC = BAC − EAC
Positive means you expect to finish under budget.
TCPI against BAC
(BAC − EV) / (BAC − AC)
The efficiency required on the remaining work to hit the original budget.
PERT three-point
(O + 4M + P) / 6
Triangular, if they say so, is (O + M + P) / 3.
Communication channels
n(n − 1) / 2
Paths among n people.
Total float
LS − ES, or LF − EF
Zero float sits on the critical path unless the project is already late.