Earned Value Management (EVM)
Measuring whether you're getting the work you're paying for, on time.
Quick Answer
Earned value management (EVM) is a project control method that compares three measures: planned value (budgeted cost of scheduled work), earned value (budgeted cost of work actually completed), and actual cost. The comparisons show whether a project is over or under budget and ahead of or behind schedule, and they support forecasts of final cost.
The Full Picture
Comparing spending to budget alone is misleading. A project that has spent half its budget might be half done, or a quarter done. Earned value management exists to tie cost and progress together, so managers can see whether the money spent bought the expected amount of work. It is formalized in the ANSI/EIA-748 standard and is required on many U.S. federal programs; the GAO Cost Estimating and Assessment Guide covers it in depth.
Mechanically, EVM uses three values. Planned value (PV) is the budget for work scheduled to date. Earned value (EV) is the budget for work actually completed. Actual cost (AC) is what was spent. Cost variance is EV minus AC, schedule variance is EV minus PV, and the ratios give the cost performance index (CPI = EV / AC) and schedule performance index (SPI = EV / PV). A CPI below 1.0 means each dollar is buying less than a dollar of planned work.
In practice on construction projects, earned value is measured through the schedule of values, quantities installed, or percent-complete rules agreed per activity. The CPI is often used to forecast the estimate at completion, for example by dividing the total budget by the current CPI, though experienced managers adjust that for known risks and remaining work.
The link to preconstruction is the baseline. EVM only works if the budget is broken down into a structure that matches how work will be tracked, and if the schedule is resource-loaded or cost-loaded. A precon estimate organized by cost code and tied to schedule activities makes EVM possible; a lump estimate with no breakdown does not.
Real Examples
Common Misconceptions
People assume: Being under budget to date means the project is healthy.
Actually: Spending less than planned can simply mean less work got done. EVM compares cost to earned value, which reveals whether low spending is savings or delay.
People assume: EVM is only for large federal programs.
Actually: The formal ANSI/EIA-748 system is common on federal work, but the core comparisons of planned value, earned value, and actual cost apply to any project with a cost-loaded schedule.
Frequently Asked Questions
What are the three key measures in earned value management?
Planned value (budgeted cost of work scheduled), earned value (budgeted cost of work performed), and actual cost (the cost actually incurred for that work). All EVM metrics are derived from these three.
How do you calculate CPI and SPI?
Cost performance index is earned value divided by actual cost. Schedule performance index is earned value divided by planned value. Values below 1.0 indicate cost overrun or schedule slippage respectively.
How is EVM used in construction?
Contractors and owners use it to track cost and schedule performance by measuring progress on cost-loaded schedule activities or schedule of values lines, then using the indices to spot problems early and forecast final cost.
How does EVM relate to cost forecasting?
EVM provides the performance data that feeds forecasts. A common forecast of estimate at completion divides the total budget by the current CPI, though managers usually refine it with judgment about remaining work and risks.
Why does preconstruction matter for EVM?
EVM needs a baseline budget broken down to match how work will be measured and tied to schedule activities. That breakdown is created from the preconstruction estimate and schedule.