Earned Value

Earned Value Management Example: A Complete Construction Project Walkthrough

A complete 12-month EVM walkthrough on a £12.4M highway junction project - from honeymoon metrics through crisis and recovery to final outturn. Month by month, with real figures.

Gather

Will Doyle

Founder & CEO, Gather · Updated Feb 2026

The formulas aren't the hard part. Knowing what to do with the numbers is. This page walks through a complete earned value management example on a construction project - month by month, with actual figures, showing exactly how the story unfolds when a project starts well, hits problems, and claws its way back. If you need the underlying EV formulas, read those first.

The Project: Highway Junction Improvement

Worked Example

A £12.4M highway junction improvement scheme procured under NEC4 Option C (target cost with activity schedule).

ParameterValue
Contract formNEC4 Option C
Target Price (BAC)£12,400,000
Planned duration12 months
Pain/gain share50/50 above and below target
Main worksJunction realignment, slip roads, drainage, signals, surfacing
Assessment periodsMonthly (last working day)

Work Breakdown Structure

Work PackageDescriptionBudget (£)% of BAC
WP1Preliminaries & site establishment1,860,00015.0%
WP2Earthworks & drainage2,480,00020.0%
WP3Structural works (retaining walls, bridge deck)3,100,00025.0%
WP4Road construction & surfacing2,976,00024.0%
WP5Traffic signals & electrical1,240,00010.0%
WP6Landscaping & finishing744,0006.0%
Total£12,400,000100%

Each work package needs measurable deliverables - metres of kerb laid, tonnes of capping placed, linear metres of drainage installed. Vague progress estimates are how EVM falls apart.

Months 1-3: The Honeymoon

Everything looks fine. Site establishment's on track, early earthworks are progressing. Nobody's looking hard at EV metrics. Why would they?

MonthPV (£)EV (£)AC (£)CV (£)SV (£)CPISPI
M1 (Apr)620,000651,000632,000+19,000+31,0001.031.05
M2 (May)1,364,0001,395,0001,358,000+37,000+31,0001.031.02
M3 (Jun)2,232,0002,294,0002,201,000+93,000+62,0001.041.03

What the numbers say: CPI 1.04 - getting £1.04 of value for every £1 spent. SPI 1.03 - 3% ahead of programme. EAC at M3: £12,400,000 / 1.042 = £11,900,192. A forecast saving of £500K. On a 50/50 pain/gain share, that's a potential £250K gain-share. Looks lovely. Won't last.

What the commercial team should actually think: Don't celebrate. Months 1-3 are prelims and bulk earthworks - the easy bits. Structural works haven't started. A CPI of 1.04 built on muck shifting tells you almost nothing about where the job's heading.

Months 4-6: The Crack Appears

Month 4 is when structural works start. The retaining wall foundations hit unexpected ground conditions - clay with pockets of peat not in the ground investigation report. A compensation event under NEC4 clause 60.1(12). The CE quotation process takes time, and meanwhile the project bleeds money while the team waits for redesigned foundations.

MonthPV (£)EV (£)AC (£)CV (£)SV (£)CPISPI
M4 (Jul)3,348,0003,100,0003,224,000-124,000-248,0000.960.93
M5 (Aug)4,588,0004,092,0004,423,000-331,000-496,0000.930.89
M6 (Sep)5,952,0005,146,0005,710,000-564,000-806,0000.900.86

Three months. That's all it took to swing from green to red. CPI dropped from 1.04 to 0.90. SPI from 1.03 to 0.86. EAC at M6: £12,400,000 / 0.901 = £13,762,486 - a £1.36M projected overrun.

About £800,000 of that overrun is the compensation event, which should adjust the target once agreed. Strip that out and the underlying overrun is closer to £562,000 - still bad, but manageable. This is why EVM and contract management can't live in silos. If you're tracking EVM without adjusting for compensation events, you're making distorted decisions.

Month 7: The Crisis Point

Three things collide in October: (1) the ground conditions CE quotation is still being assessed, (2) a statutory undertaker diverts services three weeks late blocking slip road construction, (3) rainfall is 180% of seasonal average causing 11 lost working days.

MonthPV (£)EV (£)AC (£)CV (£)SV (£)CPISPI
M7 (Oct)7,316,0006,076,0007,068,000-992,000-1,240,0000.860.83

CPI: 0.86. For every pound spent, only 86p of value is being delivered. EAC: £12,400,000 / 0.8597 = £14,424,490. A £2M+ projected overrun.

But here's what separates experienced analysis from just running formulas. You don't just report the numbers. You decompose them.

EVM Decomposition at Month 7

ComponentCV Impact (£)SV Impact (£)Recoverable?
Ground conditions CE (pending)-620,000-480,000Yes - CE adjustment to target
Statutory undertaker delay-135,000-310,000Probably - clause 60.1(5) delay
Exceptional weather (October)-87,000-250,000Partial - clause 60.1(13) weather
Base contract inefficiency-150,000-200,000No - contractor's risk
Total-992,000-1,240,000

Of the £992,000 cost variance, only £150,000 is genuinely the contractor's problem. The rest is either recoverable through CEs or partially recoverable through weather clauses. Without this breakdown, you'd be firefighting a £2M overrun. With it, you're managing a £150,000 inefficiency and processing three legitimate CEs.

Months 8-10: The Recovery

The ground conditions CE is agreed on 14 November at £843,000 (time and cost). The target price adjusts from £12,400,000 to £13,243,000. This is the new BAC.

Once a CE adjusts the target, the EVM baseline must update. Keep reporting against the original £12.4M and the numbers will never make sense - you'll show an artificial overrun that doesn't reflect actual performance. The commercial team implements recovery measures: weekend working on structural elements, accelerated drainage, and a revised construction sequence.

MonthPV (£)EV (£)AC (£)CV (£)SV (£)CPISPI
M8 (Nov)*8,622,0007,560,0008,310,000-750,000-1,062,0000.910.88
M9 (Dec)*9,945,0009,150,0009,780,000-630,000-795,0000.940.92
M10 (Jan)*10,872,00010,478,00010,890,000-412,000-394,0000.960.96

*Months 8-12 use adjusted BAC of £13,243,000. CPI has recovered from 0.86 to 0.96. Look at the trend: 0.91, 0.94, 0.96. Three consecutive months of improvement. That trajectory matters more than any single reading. Revised EAC at M10: £13,243,000 / 0.962 = £13,766,112 - a £523K overrun against the adjusted target.

Months 11-12: The Finish

The final push. Surfacing completes in a dry window. Traffic signals installation runs ahead of schedule. Landscaping is deferred by agreement with no cost impact.

MonthPV (£)EV (£)AC (£)CV (£)SV (£)CPISPI
M11 (Feb)*12,187,00011,940,00012,095,000-155,000-247,0000.990.98
M12 (Mar)*13,243,00013,243,00013,462,000-219,00000.981.00

Final outturn: Project completes on time. Total Defined Cost: £13,462,000 against adjusted target of £13,243,000. Final CPI: 0.98. Final SPI: 1.00. Final overrun: £219,000. Pain-share to contractor: £109,500.

Compare that to the Month 7 panic when numbers suggested a £2M+ overrun and a million-pound pain-share hit. This is why EVM exists - not to generate reports, but to give the commercial team enough visibility to intervene at the right moment with the right actions.

The Full EVM Dashboard: 12-Month Summary

MonthPV (£)EV (£)AC (£)CV (£)SV (£)CPISPIEAC (£)
M1 Apr620K651K632K+19K+31K1.031.0512,039K
M2 May1,364K1,395K1,358K+37K+31K1.031.0212,039K
M3 Jun2,232K2,294K2,201K+93K+62K1.041.0311,900K
M4 Jul3,348K3,100K3,224K-124K-248K0.960.9312,917K
M5 Aug4,588K4,092K4,423K-331K-496K0.930.8913,333K
M6 Sep5,952K5,146K5,710K-564K-806K0.900.8613,762K
M7 Oct7,316K6,076K7,068K-992K-1,240K0.860.8314,424K
M8 Nov*8,622K7,560K8,310K-750K-1,062K0.910.8814,553K
M9 Dec*9,945K9,150K9,780K-630K-795K0.940.9214,088K
M10 Jan*10,872K10,478K10,890K-412K-394K0.960.9613,766K
M11 Feb*12,187K11,940K12,095K-155K-247K0.990.9813,377K
M12 Mar*13,243K13,243K13,462K-219K00.981.0013,462K

*Months 8-12 use adjusted BAC of £13,243,000 following CE agreement. EAC formula used: BAC / CPI (cumulative). For all EAC methods, see EAC, ETC and TCPI.

Five Key Lessons From This Project

Lesson 1: Early CPI Is Unreliable

The CPI of 1.04 at Month 3 was real, but it was measuring the easy work. Bulk earthworks and prelims have low complexity and well-understood costs. The structural works, where the real cost risk lives, hadn't started. Always weight EVM confidence by the complexity of work completed, not just the percentage.

Lesson 2: Decompose Before You React

Month 7's CPI of 0.86 looked catastrophic. But £842,000 of the £992,000 cost variance was recoverable through compensation events. Without decomposition, the team might have slashed resources to "save money" - exactly the wrong move when the problem isn't efficiency but uncompensated change. Understanding cost and schedule variance at work package level is what makes this decomposition possible.

Lesson 3: Adjust the Baseline or the Numbers Lie

Once the ground conditions CE was agreed at £843,000, the target moved from £12.4M to £13.243M. If the team kept reporting against the original target, every month from November onwards would show an artificial overrun that doesn't reflect actual performance. Update BAC every time a CE is implemented.

Lesson 4: CPI Trend Matters More Than CPI Value

At Month 8, CPI was 0.91 - still below 1.0, still technically overspending. But the trend - 0.86, 0.91, 0.94, 0.96 - showed clear recovery. A single CPI reading is a snapshot. The trend is the film. Always report both. An S-curve makes these trends visible at a glance.

Lesson 5: EVM Without Contract Management Is Just Arithmetic

The real value of this example isn't the formulas. It's the integration with NEC4 contract mechanisms. The compensation event process, target adjustment, and pain/gain share calculation - these are what turn EVM numbers into commercial outcomes. If your EVM system doesn't connect to contract administration, you're doing half the job.

How EVM Connects to NEC4 Target Cost Management

Under NEC4 Option C, the target price is a living number. It changes every time a compensation event is implemented. Most EVM textbooks ignore this, which is why teams struggle to make earned value work on NEC contracts.

When a CE is implemented, it adjusts the Prices (the target). Your BAC must update. If it doesn't, you're measuring performance against a contract position that no longer exists.

Under NEC4, the Project Manager can disallow costs that aren't in accordance with the contract (clause 11.2(26)). Disallowed costs get stripped from Defined Cost used in the pain/gain calculation, but they still show up in actual project spend. Your EVM system needs two AC figures: AC inclusive of all costs (for project control) and AC net of disallowed costs (for commercial outturn). Most spreadsheet-based EVM setups can't do this.

On this project, the final Defined Cost was £13,462,000 against an adjusted target of £13,243,000. Overrun: £219,000. At 50/50, the contractor absorbs £109,500 and the client absorbs £109,500. If EVM had flagged the efficiency problems at Month 5 instead of Month 7, two extra months of intervention could have saved £100-150K - the difference between a small pain-share and a gain-share.

Gather's AI agent reads daily site diary entries, extracts quantities and progress data, and feeds them into an earned value model automatically. On one highways package, it flagged a CPI dip below 0.95 in Week 3 of Month 4 - three weeks before it would have surfaced in a traditional monthly review. See how it works.

Common Mistakes in Construction EVM

  1. Measuring progress by spend, not output. "We've spent 60% of the budget, so we must be 60% complete." No. EV must be measured by physical output: cubic metres excavated, metres of pipe laid, tonnes of asphalt placed. If you've spent 60% but only completed 40% of the physical work, CPI is 0.67.
  2. Never adjusting the baseline. On NEC4 Option C, the target changes with every implemented CE. If you're still measuring against the original target six months and four CEs later, your metrics are fiction.
  3. Ignoring SPI after 80% complete. SPI becomes unreliable in the final 20%. A project can finish four months late and show SPI of 1.0 at completion because EV converges on BAC. Use earned schedule analysis in the final stages instead.
  4. Treating CPI as fixed. CPI changes. A Month 3 CPI of 1.04 doesn't mean you'll finish under budget. Report the trend, not just the number.
  5. Not decomposing variances. A negative CV of -£500,000 could mean five completely different things: genuine inefficiency, unpriced change, a pending CE, front-loaded subcontractor payments, or a timing difference. Report the headline without breaking it down and you'll get the wrong reaction every time. For more, see common EVM mistakes in construction.

Quick Reference: All EVM Metrics

MetricFormulaWhat It Tells YouHealthy Range
CV (Cost Variance)EV - ACOver or under budget> 0
SV (Schedule Variance)EV - PVAhead or behind programme> 0
CPIEV / ACCost efficiency> 1.0
SPIEV / PVSchedule efficiency> 1.0
EACBAC / CPIForecast total costClose to BAC
ETCEAC - ACCost to finishDecreasing trend
TCPI(BAC - EV) / (BAC - AC)Efficiency needed to hit budget< 1.2
VACBAC - EACForecast overrun/underrun> 0

For full formula derivations, see the earned value formulas page. For the monthly reporting structure, see the EV report template.

FAQs

Earned Value in Construction: Common Questions

Practical answers from a complete project walkthrough.

Earned value management (EVM) is a project control method that compares planned progress, actual progress, and actual cost at any point during a project. In construction, it tracks physical work completed - measured in quantities like cubic metres, linear metres, or tonnes - against the baseline programme and budget. The three core metrics (PV, EV, AC) generate performance indices (CPI and SPI) that tell you whether you're over budget, behind programme, or both.
Earned value equals the percentage of work physically completed multiplied by the Budget at Completion (BAC). If BAC is £12.4M and you've completed 40% of the physical work, EV is £4,960,000. The key is measuring completion by output (quantities installed) not input (money spent). Use your work breakdown structure to measure each package separately, then aggregate. See our complete formulas guide for all calculations.
A CPI below 1.0 means you're spending more than planned for each unit of work completed. A CPI of 0.90 means you're getting 90p of value for every £1 spent - or equivalently, everything is costing 11% more than budgeted. On a £12.4M project, a sustained CPI of 0.90 forecasts a final cost of £13.78M, an overrun of £1.38M. Always decompose the variance before reacting - some overspend may be recoverable through compensation events.
NEC4 Option C uses a target cost mechanism with pain/gain share. The target price is your EVM baseline (BAC). When compensation events are implemented, the target adjusts - and BAC must update to match. The final Defined Cost is compared against the adjusted target, and the difference is shared between contractor and client at the agreed ratio (commonly 50/50). EVM gives you the early warning system to manage towards a gain-share rather than discovering a pain-share at final account.
Monthly at minimum, aligned with assessment dates. For projects over £5M, weekly EV tracking gives much earlier warning. This example showed a CPI drop from 1.04 to 0.96 in a single month (Month 4). Weekly tracking would have flagged that trend mid-month, giving the commercial team two extra weeks to respond. The cost of weekly tracking is a few hours of time. The value is measured in avoided overruns.
SPI (Schedule Performance Index) measures schedule efficiency as EV divided by PV. It works well in the first 80% of a project but becomes unreliable towards completion because EV converges on BAC regardless of actual delays. Earned Schedule (ES) converts the schedule variance into time units by asking "when was the current EV level planned to occur?" - giving a time-based metric that stays accurate through to completion. SPI at Month 12 was 1.00 on this project, but it only just made the completion date. ES would have shown the time pressure more clearly in Months 10-11.
Yes. EVM doesn't require expensive software or a dedicated planning team. A work breakdown structure, a baseline programme, and a monthly measurement of physical progress is all you need. For a £2M subcontract package, you could track EV in a spreadsheet with six work packages. The principles are identical - the complexity scales with the project, not the method. What matters is measuring output, not spend. See the EVM implementation guide for the step-by-step setup process.

Gather

See CPI problems in Week 3, not Month 4.

Gather reads daily site diary entries and updates your EV metrics automatically - so the commercial team catches cost problems three weeks earlier than traditional monthly reporting.

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