What Is a Work Package in EVM? Definition & Example

<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="#what-makes-a-work-package">What Makes a Work Package</a></li><li><a href="#work-package-sizing-the-goldilocks-problem">Work Package Sizing: The Goldilocks Problem</a></li><li><a href="#earned-value-technique-selection">Earned Value Technique Selection</a></li><li><a href="#worked-example-defining-a-work-package-on-a-30m-project">Worked Example: Defining a Work Package on a £30M Project</a></li><li><a href="#the-relationship-between-work-packages-and-control-accounts">The Relationship Between Work Packages and Control Accounts</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>A work package is the lowest level of the <a href="/en/earned-value/definitions/work-breakdown-structure">Work Breakdown Structure</a>, the level where <a href="/en/earned-value">earned value</a> is actually measured. It has a defined scope, a budget, a schedule, a start date, a finish date, and an assigned earned value technique. Everything above it in the WBS is a summary. Everything below it is task-level detail that feeds the programme but doesn't get its own EV measurement. The work package is where the rubber meets the road.</p><p>Think of it this way: the WBS is the map. The <a href="/en/earned-value/definitions/control-account">control account</a> is the territory a <a href="/en/earned-value/definitions/control-account-manager">CAM</a> manages. The work package is the individual field within that territory where you measure what's growing.</p><p>This term is part of the <a href="/en/earned-value/definitions">earned value definitions glossary</a>. For the structure that contains work packages, see <a href="/en/earned-value/definitions/work-breakdown-structure">Work Breakdown Structure</a>.</p><h2 id="what-makes-a-work-package">What Makes a Work Package</h2><p>A work package isn't just a line in a spreadsheet. It's a defined unit of work with specific attributes. Miss any of these and your EV measurement is built on sand.</p><pre class="ge-ascii-diagram ge-anim"> WORK PACKAGE DATA SHEET ============================================= WBS Code: 1.2.1.3 Title: Install Lift Shaft Steelwork ───────────────────────────────────────────── SCOPE ├── Supply &amp; install structural steel for │ lift shafts 1 and 2 (levels B1 to L6) ├── Includes: beams, columns, bracings, │ connections, holding-down bolts ├── Excludes: lift guide rails (WBS 1.3.2.1), │ fire protection (WBS 1.2.4.2) │ BUDGET ├── BAC: £280,000 ├── Labour: £95,000 ├── Plant: £35,000 ├── Material: £140,000 ├── Subcontract: £0 (in-house) ├── Prelims allocation: £10,000 │ SCHEDULE ├── Planned start: 3 March 2026 ├── Planned finish: 11 April 2026 ├── Duration: 6 weeks ├── Predecessor: WBS 1.2.1.2 (RC core walls) ├── Successor: WBS 1.3.2.1 (lift guide rails) │ EV MEASUREMENT ├── Technique: Weighted milestones ├── M1: Steel delivered to site (15%) £42,000 ├── M2: Shaft 1 complete to L3 (25%) £70,000 ├── M3: Shaft 1 complete to L6 (20%) £56,000 ├── M4: Shaft 2 complete to L3 (25%) £70,000 ├── M5: Both shafts complete (15%) £42,000 │ RESPONSIBILITY ├── CAM: D. Brown (Structural Lead) ├── Control Account: CA-02 (Superstructure) └── Approver: Project Manager ─────────────────────────────────────────────</pre><p>Every field on that data sheet matters. The scope boundary (includes/excludes) prevents double-counting. The budget breakdown enables <a href="/en/earned-value/definitions/cost-variance">cost variance</a> analysis at the resource level. The schedule ties the work package to the programme. The EV technique determines how progress is measured.</p><h2 id="work-package-sizing-the-goldilocks-problem">Work Package Sizing: The Goldilocks Problem</h2><p>Too big and you can't measure progress meaningfully. Too small and you drown in data. Getting the size right is one of the most practical challenges in setting up an EVM system.</p><p><strong>The sizing guidelines I use:</strong></p><div class="ge-table-wrap ge-anim"><table class="ge-table"><thead><tr><th>Criteria</th><th>Target Range</th></tr></thead><tbody><tr><td>Budget (BAC)</td><td>£50,000 to £2,000,000</td></tr><tr><td>Duration</td><td>2 weeks to 3 months</td></tr><tr><td>Milestones</td><td>3 to 8 per work package</td></tr><tr><td>Reporting periods</td><td>Should span 2 to 6 monthly reporting periods</td></tr></tbody></table></div><p>A £280K lift shaft package over 6 weeks with 5 milestones? That's in the sweet spot. A £15M M&amp;E package over 18 months with 2 milestones? That's a control account masquerading as a work package. Break it down further.</p><p>On a £30M project, I'd expect somewhere between 15 and 40 work packages. Fewer than 15 means the work packages are too large for granular progress measurement. More than 50 means you're probably tracking at task level, which creates an administrative burden that kills EVM adoption faster than any other mistake.</p><h2 id="earned-value-technique-selection">Earned Value Technique Selection</h2><p>Each work package gets one earned value technique (EVT). The technique determines how you convert physical progress into a pound figure for <a href="/en/earned-value/definitions/earned-value">EV</a>. Pick the wrong technique and your EV is fiction.</p><pre class="ge-ascii-diagram ge-anim"> CHOOSING THE RIGHT EVT PER WORK PACKAGE ============================================= QUESTION: Can you define clear, binary milestones? │ ├── YES ──&gt; WEIGHTED MILESTONES │ (construction packages, installations) │ Credit at each milestone completion │ └── NO ──&gt; Is the work short (&lt; 2 months)? │ ├── YES ──&gt; FIXED FORMULA (0/100 or 50/50) │ (short discrete tasks, approvals) │ 0/100: credit only at completion │ 50/50: half at start, half at end │ └── NO ──&gt; Is it a support activity with no deliverable? │ ├── YES ──&gt; LEVEL OF EFFORT (LOE) │ (site management, prelims) │ EV = PV automatically │ └── NO ──&gt; PERCENT COMPLETE (design, continuous work) Subjective – use as last resort</pre><p>I have a strong opinion on this: default to <a href="/en/earned-value/definitions/weighted-milestones">weighted milestones</a> for any physical construction work. It's the most objective technique available and it forces the team to define "done" upfront. Percent complete should be your last resort, not your default.</p><h2 id="worked-example-defining-a-work-package-on-a-30m-project">Worked Example: Defining a Work Package on a £30M Project</h2><span class="ge-worked-label">Worked Example</span><div class="ge-callout ge-anim"><p><strong>Scenario:</strong> A £30M NEC4 Option C mixed-use development in Bristol. The <a href="/en/earned-value/definitions/control-account-manager">CAM</a> for the superstructure control account (CA-02, BAC = £10.2M) needs to define individual work packages for EVM measurement.</p><p><strong>One of the work packages: Install Lift Shaft Steelwork</strong></p><div class="ge-table-wrap ge-anim"><table class="ge-table"><thead><tr><th>Attribute</th><th>Detail</th></tr></thead><tbody><tr><td>WBS Code</td><td>1.2.1.3</td></tr><tr><td>Title</td><td>Install Lift Shaft Steelwork</td></tr><tr><td>BAC</td><td>£280,000</td></tr><tr><td>Duration</td><td>6 weeks (3 Mar to 11 Apr 2026)</td></tr><tr><td>CAM</td><td>D. Brown (Structural Lead)</td></tr><tr><td>EVT</td><td>Weighted milestones (5 milestones)</td></tr></tbody></table></div><p><strong>Milestone schedule and EV plan:</strong></p><div class="ge-table-wrap ge-anim"><table class="ge-table"><thead><tr><th>Week</th><th>Milestone</th><th>Weight</th><th>Cumulative EV</th></tr></thead><tbody><tr><td>1</td><td>M1: Steel delivered to site</td><td>15%</td><td>£42,000</td></tr><tr><td>2</td><td>M2: Shaft 1 steelwork to level 3</td><td>25%</td><td>£112,000</td></tr><tr><td>3-4</td><td>M3: Shaft 1 steelwork to level 6</td><td>20%</td><td>£168,000</td></tr><tr><td>4-5</td><td>M4: Shaft 2 steelwork to level 3</td><td>25%</td><td>£238,000</td></tr><tr><td>6</td><td>M5: Both shafts complete, snag-free</td><td>15%</td><td>£280,000</td></tr></tbody></table></div><p><strong>Month-end progress (end of March 2026, week 4):</strong></p><ul><li>M1: Complete (week 1). EV = £42,000</li><li>M2: Complete (week 2). EV = £70,000</li><li>M3: Complete (end of week 3, one day early). EV = £56,000</li><li>M4: In progress (70% through shaft 2). EV = £0 (not yet complete)</li></ul><p><strong>EV at end of March = £42,000 + £70,000 + £56,000 = £168,000</strong><strong>PV at end of March = £168,000 (M1 + M2 + M3 planned by week 4)</strong><strong><a href="/en/earned-value/definitions/schedule-variance">SV</a> = £168,000 - £168,000 = £0 (on programme)</strong></p><p><strong>AC at end of March = £185,000</strong> (steel price was higher than tendered) <strong><a href="/en/earned-value/definitions/cost-variance">CV</a> = £168,000 - £185,000 = -£17,000</strong><strong><a href="/en/earned-value/definitions/cost-performance-index">CPI</a> = £168,000 / £185,000 = 0.908</strong></p><p>On programme but 9% over budget on cost. The CAM investigates: steel price has risen 6% since tender. On NEC4 Option C, this feeds into the Defined Cost and will affect the pain/gain position. If the price increase qualifies as a compensation event, <a href="/en/earned-value/definitions/budget-at-completion">BAC</a> adjusts upward. If not, it's Contractor risk absorbed into the share calculation.</p></div><h2 id="the-relationship-between-work-packages-and-control-accounts">The Relationship Between Work Packages and Control Accounts</h2><p>Work packages sit inside control accounts. A control account typically contains 3 to 10 work packages. The CAM manages all work packages within their control account and reports aggregated EVM metrics upward.</p><pre class="ge-ascii-diagram ge-anim"> CONTROL ACCOUNT → WORK PACKAGES ============================================= CA-02: Superstructure (BAC = £10,200,000) CAM: D. Brown │ ├── WP 1.2.1.1 RC columns to L2 £2,100,000 [Weighted MS] ├── WP 1.2.1.2 Slab level 1 £1,400,000 [0/100] ├── WP 1.2.1.3 Lift shaft steelwork £280,000 [Weighted MS] ├── WP 1.2.1.4 Roof slab £700,000 [0/100] ├── WP 1.2.2.1 Portal frames £2,200,000 [Weighted MS] ├── WP 1.2.3.1 Roof structure £1,600,000 [Weighted MS] ├── WP 1.2.4.1 Masonry £680,000 [% Complete] └── WP 1.2.4.2 Cladding £1,240,000 [Weighted MS] ─────────── £10,200,000 CA-02 EV = sum of all work package EVs CA-02 AC = sum of all work package ACs CA-02 CPI = CA-02 EV / CA-02 AC</pre><p>Notice the mixed EVTs: weighted milestones for most packages, 0/100 for short-duration pours, percent complete for masonry (hard to define binary milestones for continuous bricklaying). That mix is normal and healthy.</p><h2 id="common-mistakes">Common Mistakes</h2><ol><li><strong>No scope boundary definition.</strong> "Steelwork" as a work package title is ambiguous. Does it include connections? Holding-down bolts? Fire protection? The scope section of the work package data sheet must state what's included and what's excluded. Ambiguity here causes double-counting or gaps in <a href="/en/earned-value/definitions/budget-at-completion">BAC</a>.</li><li><strong>Work packages longer than 3 months.</strong> If a work package runs 6 months with no internal milestones, you'll have 5 monthly reports with no EV movement. That's not EVM. That's guessing. Break it into shorter work packages or add more milestones.</li><li><strong>Using the same EVT for everything.</strong> Percent complete for all work packages is lazy and inaccurate. Match the EVT to the work type. Physical construction: weighted milestones. Short tasks: fixed formula. Support activities: level of effort. Each work package gets the technique that fits.</li><li><strong>Confusing work packages with programme activities.</strong> A work package is a WBS element (scope). A programme activity is a schedule element (time). They're related, every work package maps to one or more activities, but they're not the same thing. One work package might contain 8 programme activities. That's fine.</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>How small should a work package be?</h3><p>The practical minimum is about £50,000 and 2 weeks' duration. Below that, the administrative overhead of measuring and reporting EV exceeds the value of the information. If you're tempted to create a £10,000 work package, ask whether it should just be a milestone within a larger package instead.</p><h3>Who defines the work packages?</h3><p>The <a href="/en/earned-value/definitions/control-account-manager">CAM</a>, in collaboration with the project controls team. The CAM knows the scope best. The project controls team ensures the work packages comply with EVM rules (100% rule, appropriate EVT, proper coding). The project manager approves the final WBS and work package definitions during the <a href="/en/earned-value/definitions/integrated-baseline-review">integrated baseline review</a>.</p><h3>Can work packages be added or changed after the baseline is set?</h3><p>Yes, through formal <a href="/en/earned-value/definitions/re-baselining">re-baselining</a>. On NEC4, a compensation event might add new scope that requires a new work package. Or a scope change might split one work package into two. Document the change, adjust <a href="/en/earned-value/definitions/budget-at-completion">BAC</a>, and update the <a href="/en/earned-value/definitions/planned-value">PV</a> curve. What you don't do is quietly add a work package and hope nobody notices the BAC has shifted.</p><h3>What's the difference between a work package and a task?</h3><p>A work package is the lowest WBS level where EV is measured and budget is assigned. A task is a programme activity that sits within a work package. The work package "Install Lift Shaft Steelwork" might contain tasks like "erect temporary works," "lift steel to level 3," "bolt connections." Tasks feed the programme. Work packages feed the EVM system. They serve different audiences.</p></article></div>