PMs: Earned Value Management, 3 EAC Formulas and a $200K Example

Earned value management (EVM) is a project performance measurement method that integrates scope, schedule, and cost into a single set of objective numbers instead of three separate, disconnected reports. Its core payoff is early warning: by comparing planned value, earned value, and actual cost, you can see whether a project is behind, over budget, or both, often months before a status meeting would reveal it. That objectivity is why the Department of Energy and defense agencies require it on major programs.

TL;DR:

Negative cost variance and schedule variance patterns indicate whether a project is experiencing cost overruns or delays, requiring root cause analysis.

Accurate EVM relies on a solid performance measurement baseline and appropriate earning rules matched to task risk profiles.

Forecasting methods like EAC depend on judgment: whether current performance trends will continue or if variances are temporary anomalies.

Consistent owner-ship of the EVM process and proper baseline management are crucial for trustworthy data, especially in large or high-risk programs.

EVM metrics such as CPI and SPI become meaningful only after sufficient project progress, typically around 20%, and require careful interpretation within detailed control account structures.

What Are the Core Components of Earned Value Management?
What Are the EVM Formulas for Cost and Schedule Variance?
How Do You Diagnose Cost and Schedule Variance Patterns?
How Do You Forecast With EAC, ETC, and TCPI?
What Standards Govern Earned Value Management Systems?
How Do You Set Up an EVM Process Step by Step?
What Does a Sample EVM Calculation Look Like?
What Should You Look for in EVM Reporting Tools?
MSI’s Role in Building EVM Skills
When Do You Need Full EVMS Versus a Lightweight Approach?
MSI’s Six Sigma Training and Earned Value Skills
Standards and Guides Worth Bookmarking
Sources
FAQ

What Are the Core Components of Earned Value Management?

Every EVM calculation rests on three numbers, and if you get these wrong, everything downstream is noise.

Planned Value (PV) is the budgeted cost of the work you scheduled to complete by a given date. If a $100,000 phase was supposed to be 40% done by today, your PV is $40,000, regardless of what actually happened.

Earned Value (EV) is the budgeted cost of the work you actually completed, measured against that same baseline budget. If your crew finished 30% of that phase, EV is $30,000, even if they spent $50,000 getting there.

Actual Cost (AC) is simply what you spent. No adjustments, no interpretation. Just the invoices, timesheets, and purchase orders tied to that work.

All three numbers only mean something if they sit on a solid performance measurement baseline (PMB), the time-phased budget plan against which everything is measured. A baseline built on padded estimates, unapproved scope, or a schedule nobody actually follows will generate confident-looking variances that are simply wrong. PMI’s Standard for Earned Value Management treats baseline integrity as the foundation the entire methodology depends on, not an administrative afterthought.

How you calculate EV depends on your earning rule, and picking the wrong one for the task at hand is one of the most common EVM mistakes:

0/100: No credit until the work package is fully complete. Best for short-duration tasks (under a reporting period) where partial credit invites gaming, like a single deliverable or a procurement milestone.
50/50: Half the budget credited at start, half at finish. Works for tasks with unpredictable middles, but clear start/end points, such as testing cycles.
20/80: A smaller portion (20%) credited at start, the rest at completion. Useful when starting the work carries real cost but finishing is what matters most, like design reviews.
Percent complete (subjective): A supervisor estimates progress. Flexible, but the most prone to overstatement and the hardest to audit.
Units complete (objective): Credit tied to a physical count, like linear feet of cable pulled. The most defensible rule when the work supports it.

Match the rule to the task’s risk profile, not to whichever one makes the schedule look best this week.

What Are the EVM Formulas for Cost and Schedule Variance?

Once PV, EV, and AC are set, the calculations are simple arithmetic. The interpretation is where the actual skill lives.

Cost Variance (CV) = EV − AC
Schedule Variance (SV) = EV − PV
Cost Performance Index (CPI) = EV / AC
Schedule Performance Index (SPI) = EV / PV

CV and SV are expressed in currency (dollars, euros, whatever your project uses), so keep every input in the same currency and the same reporting period. Mixing a cumulative AC with a current-period PV is a common data error that quietly corrupts every ratio downstream.

Pro Tip: Always confirm whether your report is showing cumulative-to-date figures or current-period figures before comparing CPI or SPI across reporting cycles. Comparing a cumulative CPI to a single-period SPI will produce a misleading trend line even when both numbers are individually correct.

Negative CV means you’re spending more than the value of work delivered, a cost overrun. Negative SV means less work got done than planned, a schedule slip. Positive numbers mean the opposite in each case.

CPI and SPI are ratios, and the number 1.0 is the line between healthy and unhealthy performance:

A CPI of 0.85 means you are getting roughly 85 cents of earned value for every dollar spent. An SPI of 0.90 means the project has completed about 90% of the work it should have by this point in the schedule.

CPI below 1.0 signals cost inefficiency; above 1.0 signals you’re spending less than the work is worth (rare, and worth double-checking your data before celebrating). SPI works the same way for schedule. Wikipedia’s summary of EVM lays out these same formulas as the standard reference point most practitioners cite. One caveat worth remembering: these indexes become genuinely predictive only after a project has enough completed work behind it, roughly 20% progress, for current performance trends to mean much of anything.

How Do You Diagnose Cost and Schedule Variance Patterns?

Numbers alone don’t tell you what to fix. Pattern recognition does.

A negative CV paired with a positive SV is a classic sign of overtime or expedited resources: the team is ahead of schedule but burning extra cash to get there. A negative SV with a positive CV often signals resource shortages, work sitting idle while costs stay controlled because the idle time isn’t being spent on much of anything.

SV has a well-known blind spot: it approaches zero as a project nears completion, since there’s less remaining work left to be “behind” on, even if the project finished weeks late. That’s why experienced practitioners cross-check SV trends against a critical-path schedule analysis rather than trusting the index alone near project close. SV tells you about the volume of work, not which work, so a project can show positive SV while its most schedule-critical tasks are quietly slipping.

Several data problems recur often enough to name directly:

Subjective percent-complete estimates that get rounded up to look better than reality, a pitfall research on EVM metrics flags as one of the most common accuracy killers.
Incorrect PV, usually from a baseline that was never updated after an approved scope change.
Timing mismatches, where AC reflects costs incurred in a different period than the EV they’re supposed to be measured against.
Control account fragmentation, where work gets tracked at a level too granular or too coarse to give a meaningful earning signal.

How Do You Forecast With EAC, ETC, and TCPI?

Once you know where a project stands, the real question is where it’s headed. That’s what forecasting metrics answer.

Estimate at Completion (EAC) projects the total cost of the project given current performance. Three common formulas serve different situations:

EAC = AC + (BAC − EV): assumes remaining work will be completed at the planned rate, ignoring current cost performance. Use only when the cause of the variance was a one-time event, not a trend.
EAC = BAC / CPI: assumes current cost efficiency will hold for the rest of the project. The most widely used default.
EAC = AC + [(BAC − EV) / (CPI × SPI)]: assumes both cost and schedule pressures will continue to compound. More conservative, and often more realistic on troubled projects.

Choosing among them depends on a judgment call: is the current variance a blip, or a trend? PMI’s guidance frames this as the central forecasting decision practitioners have to make, and it’s worth revisiting that judgment every reporting cycle rather than locking in one formula for the life of the project.

Estimate to Complete (ETC) should come from a bottom-up, objective reassessment of the remaining work, not simply EAC minus AC. Treating ETC as a subtraction exercise hides real risk in the work that’s left, since it inherits every assumption baked into the EAC formula you picked.

To-Complete Performance Index (TCPI) tells you the cost efficiency the remaining work must hit to finish on budget: TCPI = (BAC − EV) / (BAC − AC). A TCPI far above your current CPI is an early signal that the current budget is no longer realistic without a scope, schedule, or funding change.

What Standards Govern Earned Value Management Systems?

EVM stops being a spreadsheet exercise and becomes an EVM System (EVMS) when an organization formalizes the processes, controls, and data integration that produce those numbers reliably across every project. The governing standard, EIA-748D, lays out 32 guidelines organized around organization, planning and budgeting, accounting, analysis, and revisions.

One principle from that standard matters more than the rest combined:

An EVMS is owned by the performing organization, not by any single software vendor or contract requirement. The system must integrate scope, schedule, and cost into one performance measurement baseline that the organization maintains and defends over the project’s life.

That ownership clause is why two organizations using the same software can have wildly different EVMS maturity. The tool doesn’t create discipline; the organization’s processes do.

Government contracting adds specific thresholds and acceptance procedures. The Department of the Navy’s implementation guide walks through EVMS acceptance reviews, documentation requirements, and the tailoring and negotiation that happens before a contract’s reporting level gets locked in. The DOE applies similar thresholds on capital projects, scaling documentation to program size and risk rather than applying one rigid template everywhere.

Practical scaling guidance for organizations not bound by a contract mandate:

Small internal projects: a lightweight baseline, consistent earning rules, and monthly variance review is often enough.
Mid-size programs with multiple stakeholders: formal control accounts and a documented change process.
Large or high-risk programs: full EIA-748D compliance, with surveillance reviews and a dedicated EVMS analyst role.

How Do You Set Up an EVM Process Step by Step?

Standing up EVM well is less about software and more about sequencing the setup correctly the first time.

Build the Work Breakdown Structure (WBS) down to a level where each work package has a clear owner and a measurable output.
Establish control accounts that map the WBS to your cost accounting system so budget and actual costs align at the same level of detail.
Assign earning rules to each work package before work starts, not retroactively once someone asks how “done” it is.
Get baseline approval from a sponsor or change control board so the PMB carries real authority, not just a planner’s best guess.
Set a reporting cadence, typically monthly, aligned so cost data and schedule updates land in the same window rather than weeks apart.
Run variance analysis routinely, flagging any CV or SPI that crosses a predefined threshold for a documented explanation.
Route approved scope or budget changes through change control before touching the baseline, and log every revision.

Pro Tip: Assign one person clear ownership of baseline integrity. When cost data, schedule updates, and earning-rule decisions all flow through a single accountable role, EVM data stays trustworthy. Split across three departments with no coordination, and it degrades within a quarter.

What Does a Sample EVM Calculation Look Like?

Here’s a compact snapshot from a hypothetical $200,000 project, three months in, to show the math end to end.

Metric	Value
Budget at Completion (BAC)	$200,000
Planned Value (PV)	$80,000
Earned Value (EV)	$70,000
Actual Cost (AC)	$85,000

Working through it:

CV = $70,000 − $85,000 = −$15,000 (over budget)
SV = $70,000 − $80,000 = −$10,000 (behind schedule)
CPI = $70,000 / $85,000 = 0.82
SPI = $70,000 / $80,000 = 0.88
EAC (using BAC/CPI) = $200,000 / 0.82 = $243,902

At an SPI of 0.88 and CPI of 0.82, this project is both behind and over budget, and the projected overrun is roughly $44,000 above the original plan. The immediate action isn’t panic, it’s root-cause analysis: pull the underlying work packages and find out whether one late vendor delivery or a systemic estimating error is driving both numbers. Real projects rarely show numbers this clean; multiple control accounts moving in different directions is the norm, which is exactly why aggregate CPI and SPI need to be checked against the account-level detail before you draw conclusions.

What Should You Look for in EVM Reporting Tools?

Software doesn’t create good EVM data, but the right reporting setup makes disciplined tracking far less painful. At minimum, expect a reporting platform to generate:

PV/EV/AC time series charts showing cumulative performance against the baseline over the life of the project.
CPI/SPI trend lines so you catch a drifting index before it becomes a crisis.
EAC forecasts updated automatically as new actuals come in.
TCPI dashboards highlighting when the required efficiency for remaining work exceeds what the team has actually been delivering.

On the integration side, look for clean mapping between your cost ledger and the WBS, direct linkage to the schedule tool so SV reflects real critical-path data, and version control on the baseline so nobody can quietly edit history. At the category level, prioritize an audit trail, configurable earning rules per work package, and exportable reports your finance team can reconcile without a translation layer.

MSI’s Role in Building EVM Skills

Management and Strategy Institute has certified more than 300,000 professionals across its process improvement and business management programs, with a 98% recommendation rating from alumni. That scale reflects a straightforward model: comprehensive study materials and a certification exam bundled into one upfront fee, with no hidden costs added later.

Michael, the author of this guide, focuses on translating standards-based methodologies like EVM into practical steps that project professionals can apply without a compliance department behind them. MSI’s Six Sigma and project management curricula cover the statistical thinking and variance analysis skills that make EVM data meaningful rather than just mathematically correct.

When Do You Need Full EVMS Versus a Lightweight Approach?

Full EIA-748D compliance makes sense when a contract requires it, when the program is large or high-risk enough that surveillance reviews add real value, or when multiple stakeholders need audited, defensible numbers. Watch for these signals: fixed-price government contracts, multi-year programs with executive-level funding scrutiny, or a history of scope creep that’s already burned trust with a sponsor.

Most internal projects don’t need that weight. Build that lightweight habit first. The discipline transfers directly if a future program demands the full standard.

MSI’s Six Sigma Training and Earned Value Skills

Reading the formulas is one thing. Applying them under a live budget crunch, with a sponsor asking why CPI dropped, is another. That gap is where structured training earns its keep, and it’s the gap Management and Strategy Institute built its programs to close.

MSI’s Six Sigma certification programs teach the statistical and process-control thinking that sits underneath solid EVM practice: understanding variance, distinguishing signal from noise, and building the kind of disciplined baseline that makes CPI and SPI worth trusting in the first place. Every program bundles study materials and the certification exam into one all-inclusive fee, so there are no surprise costs partway through. You can start with a Free Business Management Training module if you want a low-commitment first step, or move straight into the Six Sigma certification package deals packages built for professionals ready to formalize their credentials. For a full curriculum built around the Six Sigma methodology from the ground up, the Ultimate Six Sigma Certification Course Package covers the belt levels professionals use to demonstrate process improvement expertise on their resume. Check the current package options and pick the level that matches where your project work stands today.

Standards and Guides Worth Bookmarking

For verification or deeper study, these primary sources cover the ground this article draws from directly.

PMI’s Standard for Earned Value Management: the methodology-level reference for how EVM integrates scope, schedule, and resources.
EIA-748D: the technical standard defining EVMS guidelines and organizational ownership.
Department of Energy EVM guidance: federal capital-project application and baseline requirements.
Department of the Navy EVM Implementation Guide: contract-level acceptance, tailoring, and documentation procedures.

Sources

FAQ

How Is EVM Calculated?

EVM starts with three inputs, Planned Value, Earned Value, and Actual Cost, then derives Cost Variance (EV − AC), Schedule Variance (EV − PV), CPI (EV / AC), and SPI (EV / PV) from those baseline numbers.

How Do You Get Certified in EVM?

There’s no single universal EVM-only certification, but project management and process improvement credentials, including Six Sigma certification through Management and Strategy Institute, build the statistical and variance analysis skills EVM practice depends on.

What Is a Good EAC Formula to Use?

The most common default is EAC = BAC / CPI, which assumes current cost efficiency continues for the rest of the project; use the more conservative CPI times SPI version when both cost and schedule pressures look likely to persist.

Is EVM a KPI?

EVM itself is a measurement methodology, not a single KPI, but the metrics it produces, CPI, SPI, CV, and SV, function as key performance indicators that feed directly into project status reporting and forecasts.