What Is CPI & SPI?
Earned Value Management for Construction
Your PM says "CPI is 0.91." Everyone nods. Nobody understands: for every dollar spent, you've earned 91 cents of value. Your $12M project is on track to cost $13.2M. And SPI at 0.84 means you're earning value at 84% of the planned rate. You are over budget AND behind schedule.
CPI (Cost Performance Index) and SPI (Schedule Performance Index) are the two core ratios of Earned Value Management. Together, they tell you whether your project is on track — with mathematical precision, not gut feeling.
How Earned Value Works — 3 Inputs, 2 Ratios
EVM reduces your entire project to three dollar values: what you planned, what you earned, and what you spent. From those, CPI and SPI reveal the truth.
Define Planned Value (PV)
PV is the budgeted cost of work scheduled — what you planned to accomplish by today. It comes from your cost-loaded baseline schedule. At month 6 of a $12M project, if you planned to be 40% complete, PV = $4.8M. This is your yardstick.
Measure Earned Value (EV)
EV is the budgeted cost of work performed — what you actually accomplished, measured in budget dollars. If you are 35% complete on a $12M project, EV = $4.2M. The difference between EV and PV is your Schedule Variance: you earned $4.2M of value but should have earned $4.8M.
Compare Against Actual Cost (AC)
AC is what you actually spent to earn that value. If you spent $4.6M to achieve $4.2M of value, your CPI = 4.2/4.6 = 0.91. For every dollar spent, you got 91 cents of value. Your SPI = 4.2/4.8 = 0.88. You are earning value at 88% of the planned rate.
The EVM Formula Tree — From Inputs to Insight
Three values in, two ratios out, one quadrant that tells you exactly where your project stands. Watch how PV, EV, and AC flow into CPI, SPI, and the project health quadrant.
How POD Makes EVM Automatic
The reason 67% of projects lack EVM is the data burden. POD eliminates it by deriving all three EVM inputs from daily field data.
Live CPI & SPI Gauges
POD calculates CPI and SPI daily from field production data and cost reports. See your speedometers update in real time — not at the monthly project review when the overrun is already locked in.
S-Curve Visualization
The classic earned value S-curve — Planned Value, Earned Value, and Actual Cost plotted over time. POD generates this automatically from daily data, with the gap between curves telling the story of your project.
Estimate at Completion (EAC)
POD projects your final cost using multiple EAC formulas: EAC = BAC/CPI (if trends continue), EAC = AC + (BAC-EV)/CPI*SPI (factoring schedule). See the most likely finish cost today, not at completion.
Variance Decomposition
When CPI drops, POD tells you why — which trades, which activities, which cost categories are driving the overrun. Don't just know you're over budget. Know exactly where the money is going.
Earned Value — CPI and SPI Calculated From Your Daily Data
These KPIs auto-populate from daily field production data and cost reports. CPI and SPI update every day — not every month.
Progress S-Curve
Earned Value Intelligence Features
EVM Quadrant Analysis
Plot your project on the 2x2 quadrant: on/over budget vs ahead/behind schedule. See which quadrant you are in and what actions to take.
Cost Variance (CV) Tracking
CV = EV - AC. A negative CV means you are over budget. POD tracks cumulative and periodic CV to show whether the overrun is growing or stabilizing.
Schedule Variance (SV) in Days
Convert SV from dollars to days using SV(t). POD tells you not just that you are behind, but by how many calendar days — the metric owners actually understand.
To-Complete Performance Index
TCPI tells you the CPI you need to achieve from now to finish on budget. If TCPI exceeds 1.0, you need better-than-past performance to recover. POD calculates this daily.
Frequently Asked Questions
Know Your CPI and SPI. Every Day. Automatically.
POD calculates earned value from daily field data — no spreadsheet integration, no monthly reconciliation, no guessing. See your CPI and SPI update in real time.