Units Complete Method: EV Measurement for Construction

<div class="ge-article-wrapper"><nav class="ge-toc" aria-label="Table of contents"><p class="ge-toc-label">In this article</p><ul class="ge-toc-list"><li><a href="#the-formula">The Formula</a></li><li><a href="#how-units-complete-works-visually">How Units Complete Works Visually</a></li><li><a href="#when-to-use-units-complete">When to Use Units Complete</a></li><li><a href="#worked-example-duct-installation-on-a-data-centre-project">Worked Example: Duct Installation on a Data Centre Project</a></li><li><a href="#why-units-complete-beats-percent-complete">Why Units Complete Beats Percent Complete</a></li><li><a href="#common-mistakes">Common Mistakes</a></li><li><a href="#frequently-asked-questions">Frequently Asked Questions</a></li></ul></nav><article class="ge-article-body"><p>The units complete method is the most honest way to measure <a href="/en/earned-value/definitions/earned-value">earned value</a> on repetitive construction work. Instead of asking a site engineer "what percentage complete are you?", a question that invites optimism, guesswork, and outright fiction, you count things. Piles installed. Metres of duct laid. Panels erected. If you've got 500 piles to install and 340 are in the ground, you don't need anyone's opinion on progress. It's 68%. Done.</p><p>This method is part of the <a href="/en/earned-value/definitions">earned value definitions glossary</a>. For the broader set of EVM formulas, see the <a href="/en/earned-value/formulas">earned value formulas page</a>.</p><h2 id="the-formula">The Formula</h2><div class="ge-formula-box ge-anim"><span class="ge-formula-label">Formula</span><code>EV = (Units Completed / Total Units) x BAC</code></div><p>Or at work package level:</p><p><strong>EV = Units Completed x Budget Per Unit</strong></p><p>Both give you the same number. The first is a percentage approach; the second is a rate-based approach. Pick whichever makes more sense for how your team thinks about the work.</p><p>The beauty of this method is that <a href="/en/earned-value/definitions/budget-at-completion">BAC</a> and unit count come from the contract (or the priced work package), and units completed come from site records. There's minimal subjectivity. Either the pile is in the ground or it isn't.</p><h2 id="how-units-complete-works-visually">How Units Complete Works Visually</h2><pre class="ge-ascii-diagram ge-anim">UNITS COMPLETE METHOD – Piling Example ========================================= Total Piles: 500 Budget Per Pile: £4,000 BAC: 500 x £4,000 = £2,000,000 Progress at Month 4: +--+--+--+--+--+--+--+--+--+--+ |##|##|##|##|##|##|##| | | | Each block = 50 piles +--+--+--+--+--+--+--+--+--+--+ 50 100 150 200 250 300 340 |<---- COMPLETED: 340 ---->|<- REMAINING: 160 ->| EV Calculation: +-----------------------------------------------+ | Units Complete: 340 | | Total Units: 500 | | % Complete: 340 / 500 = 68.0% | | | | EV = 340 x £4,000 = £1,360,000 | | OR | | EV = 68.0% x £2,000,000 = £1,360,000 | +-----------------------------------------------+ Actual Cost to date: £1,428,000 CPI = £1,360,000 / £1,428,000 = 0.952 --> Each £1 spent is generating £0.95 of value</pre><h2 id="when-to-use-units-complete">When to Use Units Complete</h2><p>Not every work package suits this method. It works brilliantly for some and terribly for others.</p><p><strong>Ideal for:</strong></p><ul><li>Piling (number of piles)</li><li>Brickwork or blockwork (m2 of wall)</li><li>Road surfacing (m2 or linear metres)</li><li>Pipe installation (linear metres)</li><li>Precast panel erection (number of panels)</li><li>Cable pulling (linear metres)</li><li>Kerbing and edging (linear metres)</li><li>Structural steelwork (tonnes erected or number of connections)</li></ul><p><strong>Not suitable for:</strong></p><ul><li>Design work (can't count "units" of design)</li><li>Management and supervision (that's Level of Effort)</li><li>One-off fabrication or installation</li><li>Work with highly variable unit complexity</li></ul><p>The rule of thumb: if you can walk the site and count completed items, units complete is your method. If you can't, use <a href="/en/earned-value/definitions/weighted-milestones">weighted milestones</a> or percent complete instead.</p><h2 id="worked-example-duct-installation-on-a-data-centre-project">Worked Example: Duct Installation on a Data Centre Project</h2><span class="ge-worked-label">Worked Example</span><div class="ge-callout ge-anim"><p><strong>Scenario:</strong> A £45M data centre build in West London. The M&amp;E subcontractor has a work package for underfloor cable duct installation across two server halls.</p><p><strong>Work Package Details:</strong></p><ul><li>WBS Element: 3.2.4, Underfloor Cable Ducts</li><li>Total quantity: 12,000 linear metres</li><li>Budget: £960,000 (£80 per linear metre)</li><li>Duration: 14 weeks (17 February to 26 May 2026)</li><li>EVT: Units Complete</li><li><a href="/en/earned-value/definitions/control-account-manager">Control Account</a>: CA-008 (M&amp;E First Fix)</li></ul><p><strong>Monthly Progress:</strong></p><div class="ge-table-wrap ge-anim"><table class="ge-table"><thead><tr><th>Reporting Date</th><th>Metres Installed</th><th>Cumulative</th><th>EV</th><th>AC</th><th>CPI</th></tr></thead><tbody><tr><td>14 Mar 2026</td><td>2,800</td><td>2,800</td><td>£224,000</td><td>£231,000</td><td>0.970</td></tr><tr><td>11 Apr 2026</td><td>3,400</td><td>6,200</td><td>£496,000</td><td>£518,000</td><td>0.958</td></tr><tr><td>9 May 2026</td><td>3,100</td><td>9,300</td><td>£744,000</td><td>£789,000</td><td>0.943</td></tr><tr><td>26 May 2026</td><td>2,700</td><td>12,000</td><td>£960,000</td><td>£1,024,000</td><td>0.938</td></tr></tbody></table></div><p><strong>What the numbers tell us:</strong></p><p>The CPI is declining, from 0.970 in month 1 to 0.938 at completion. Each linear metre is costing progressively more than budgeted. At £80/m budgeted versus £85.33/m actual (£1,024,000 / 12,000), the overrun is £64,000.</p><p>On investigation, the second server hall had more complex routing around existing services, pushing labour hours up. The budget assumed a uniform £80/m rate across both halls. That's a lesson for next time: if unit complexity varies, consider splitting into two work packages with different rates.</p></div><h2 id="why-units-complete-beats-percent-complete">Why Units Complete Beats Percent Complete</h2><p>I've got a strong opinion on this one. Wherever you can use units complete, use it.</p><p>Percent complete relies on someone's subjective assessment. "I reckon we're about 75% done." That assessment is wrong more often than it's right, and it's almost always optimistic. There's even a name for it in the industry: the 90% syndrome. Work sits at "90% complete" for weeks because the last 10% is where all the problems live.</p><p>Units complete eliminates that game entirely. You can't claim a pile is installed when it isn't. You can't say 75% of the duct is laid when site records show 6,200 out of 12,000 metres. The numbers are verifiable, auditable, and honest.</p><p>The <a href="/en/earned-value/definitions/eia-748-standard">EIA-748 standard</a> specifically identifies units complete as a "discrete" earned value technique, meaning EV is earned based on measurable, objective criteria. That's what makes it credible.</p><h2 id="common-mistakes">Common Mistakes</h2><ol><li><strong>Using an average rate when unit complexity varies.</strong> If the first 200 piles are in open ground and the last 100 are next to a live railway, they don't cost the same. Split the work package or weight the rates. Otherwise your <a href="/en/earned-value/definitions/cost-performance-index">CPI</a> will look great early and terrible late.</li><li><strong>Counting partially complete units.</strong> A pile that's been bored but not concreted isn't a completed unit. Define "complete" clearly in the <a href="/en/earned-value/definitions/wbs-dictionary">WBS dictionary</a> and stick to it. Half-done units earn zero EV. That's the rule.</li><li><strong>Not reconciling site counts with EVM data.</strong> If the site diary says 340 piles and the EVM spreadsheet says 360, you've got a data integrity problem. Reconcile monthly. Better yet, use a system that pulls from the same source, one version of the truth.</li><li><strong>Applying units complete to non-repetitive work.</strong> Installing 50 identical precast panels? Units complete. Building one bespoke plant room? Not units complete. Don't force the method where it doesn't fit. Use <a href="/en/earned-value/definitions/weighted-milestones">weighted milestones</a> instead.</li></ol><div class="ge-product-note ge-anim"><p><strong>How Gather helps.</strong> Gather's AI reads your site diaries daily and maps progress against your cost-loaded programme, giving you accurate earned value data without manual spreadsheet updates. <a href="https://gatherinsights.com/contact">Book a demo</a> to see it working on a live NEC4 project.</p></div><h2 id="frequently-asked-questions">Frequently Asked Questions</h2><h3>What's the difference between units complete and percent complete?</h3><p>Units complete measures progress by counting finished physical items, piles, metres, panels. Percent complete asks someone to estimate how far through the work they are. Units complete is objective and verifiable. Percent complete is subjective and prone to optimism bias. Use units complete wherever the work involves repetitive, countable outputs.</p><h3>Can you use units complete for mixed-complexity work?</h3><p>You can, but you need to be careful. If some units are significantly harder than others, a single rate per unit will distort your CPI as the mix shifts. The better approach is to split the <a href="/en/earned-value/definitions/work-package">work package</a> into sub-packages with different rates, or use a weighted approach where complex units earn more EV than simple ones.</p><h3>How do you handle rework with units complete?</h3><p>Rework is a cost, not negative progress. If you installed 340 piles and 5 need reworking, your EV is still based on 340 completed piles. The rework cost hits <a href="/en/earned-value/definitions/actual-cost">actual cost</a> but doesn't reduce EV. Your CPI will drop to reflect the inefficiency, which is exactly what it should do.</p><h3>Does units complete work for NEC4 Option A activity schedules?</h3><p>Yes. Under NEC4 Option A, the activity schedule defines lump sum activities. If an activity covers 500 piles, you can use units complete within that activity to measure EV. The activity's budget divided by the unit count gives your rate. Just make sure the <a href="/en/earned-value/definitions/accepted-programme">Accepted Programme</a> aligns with the unit production rate so your <a href="/en/earned-value/definitions/schedule-performance-index">SPI</a> is meaningful.</p></article></div>