Earned Value Management: Four Numbers That Predict a Project’s End

A 0.80 CPI standing on a 0.90 SPI excuse is not running late — it’s a burn rate outrunning production. EVM names the disease months before the over-run report does, and it gives you time to change the outcome instead of just explaining it.

Every project report already knows the ending before it admits it. The schedule slips, the costs creep, and no single number ever explained why — until the final invoice lands and everyone is surprised. Earned Value Management (EVM) replaces that surprise with a small set of live numbers. They don’t grade the past; they forecast the end. A cost performance index of 0.80 built into a $100,000 project projects a $125,000 finish — visible in month four, not month ten, with enough time to either change the plan or change the baseline. This guide walks you through the core EVM formula set, shows you exactly which number to trust when, and gives you a template you can run in Excel.

Start From Three Raw Numbers

Everything in EVM derives from three observations plus a baseline:

• Planned Value (PV)= % Planned Complete × Budget at Completion (BAC)
• Earned Value (EV)= % Actual Complete × BAC
• Actual Cost (AC)= what you’ve actually spent

The weak link is honest, objective “percent complete.” Choose a measurement rule —0/100(credit only when done),50/50(half at start, half at end),20/80, or milestone-based — and apply it consistently. The formula set is only as honest as this input.

Read the Two Variances

Measure	Formula	What it says
Schedule Variance (SV)	EV − PV	Negative = behind plan
Cost Variance (CV)	EV − AC	Negative = spent more than the work is worth

Read the Two Indexes

• Schedule Performance Index (SPI) = EV ÷ PV— 0.90 means completing work at 90% of the planned pace. <1 = late.
• Cost Performance Index (CPI) = EV ÷ AC— 0.80 means getting 80 cents of value per dollar spent. <1 = over budget.

The pairing matters, and PMI is explicit about it: aCPI of 0.80 with an SPI of 0.90is a particular warning — slightly behind schedule but meaningfully over budget, which usually means you’re burning resources faster than you’re producing results, not simply running late. Different problems, different fixes. The numbers flag it; you diagnose it.

Forecast the Finish With EAC

The Estimate at Completion (EAC) is where EVM earns its keep. Pick the formula that matches your assumption:

Scenario	Formula
Current performance continues	EAC = BAC ÷ CPI
Future work follows the original plan	EAC = AC + (BAC − EV)
Original estimate was flawed	EAC = AC + ETC
Both cost & schedule need correction	EAC = AC + [(BAC − EV) ÷ (CPI × SPI)]

A companion, theTo-Complete Performance Index (TCPI), flips the question: it’s the efficiency you’d need from here on to still finish on budget —TCPI = (BAC − EV) ÷ (BAC − AC). When TCPI climbs well above your current CPI, you’re looking at a target you probably can’t hit without a real change of plan.

Build an EVM Tracker in Excel

1. Baseline sheet— list work packages with their budget and measurement rule. Sum = BAC.
2. Period sheet— each period, log % complete and Actual Cost per work package.
3. Computed columns— EV (= %complete × packages budget), PV (planned % × budget), AC.
4. KPI block— SV, CV, SPI, CPI, then EAC and TCPI with the formula matched to your assumption.
5. Trend rows— keep CPI/SPI per period so you see the curve, not a snapshot.

Worked Example

A $100,000 project at the midpoint planned to have 50% of the work done (PV = $50,000), but the team completed only 40% (EV = $40,000) and spent $60,000 to do it (AC = $60,000):

• SV= 40,000 − 50,000 =−$10,000(behind)
• CV= 40,000 − 60,000 =−$20,000(over budget)
• SPI= 40,000 ÷ 50,000 =0.8
• CPI= 40,000 ÷ 60,000 =0.67
• EAC= 100,000 ÷ 0.67 ≈$149,000(if performance holds — a red flag you can act on now)

That’s the entire point of the discipline: not to grade the past, but to give you time to change the outcome.

Where EVM Fits (and Where It Doesn’t)

EVM suits projects with measurable, discriminable work — construction, engineering, defense, software with defined deliverables. The ISO 21508:2025 standard formalizes the practice for project, programme, and portfolio management. It works best where “percent complete” is objective.

It struggles where it can’t: research-style work with no clean output measure, or tiny projects where the tracking overhead exceeds the benefit. And remember PMI’s caution — a CPI or SPI is asignal, not an answer. The number tells you something happened; interpretation tells you why, what it means next, and whose call it is to act.

Common Mistakes

• Faking percent complete.An inflated EV turns ERV into a self-congratulation tool.
• Reading only CPI.Cost and schedule are different diseases; check both.
• Using the wrong EAC assumption.Delegating “typical” vs “atypical” silently changes the forecast.
• Forecasting with stale data.A snapshot a month old is history, not a forecast.
• Letting the tool make the call.Automation removes the excuse for missing numbers, not the responsibility for reading them.

Frequently Asked Questions

What’s the difference between CPI and SPI?CPI (cost) = EV ÷ AC tells you value per dollar; SPI (schedule) = EV ÷ PV tells you pace. A project can be on schedule and bleeding cash, or on budget and running late — you need both.

How do I pick a percent-complete rule?Use 0/100 for items you can’t verify partway through, 50/50 for short tasks, and milestone-based for longer work packages. Consistency beats cleverness.

Does EVM require special software?No. You can run the formula set on top of Jira, Asana, Smartsheet, or a spreadsheet. The platform matters less than the quality of the inputs — honest percent complete and real actual costs.

Is EVM only for big organizations?EVM scales to any project with definable work. Standard EVM is mandatory in some defense and government engagements, but small teams can use the same four numbers with far less ceremony.

Stop Being the Last One to Know

The budget was always going to reveal itself. EVM just makes it reveal itself now — with enough lead time to change the trajectory instead of absorbing the surprise. Baseline your BAC, log honest percent complete, and let CPI, SPI, EAC, and TCPI do the forecasting your month-end report was meant to.

Keep the monthly pacing and the baseline discipline in amonthly budget planner habit, and log every actual against areceipt-style expense trackerso the AC column comes from facts, not memory. More free tools live atUse Office Toolkit.