NEC4 Early Warning Notice: EVM Triggers & Risk Management

<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-clause-16-actually-requires">What Clause 16 Actually Requires</a></li> <li><a href="#how-evm-metrics-work-as-early-warning-data">How EVM Metrics Work as Early Warning Data</a></li> <li><a href="#worked-example-cpi-drop-on-a-15m-highways-package">Worked Example: CPI Drop on a £15M Highways Package</a></li> <li><a href="#the-early-warning-register">The Early Warning Register</a></li> <li><a href="#setting-your-early-warning-thresholds">Setting Your Early Warning Thresholds</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>An NEC4 early warning notice is a formal notification under clause 16 that something could increase the total of the Prices, delay Completion, delay meeting a Key Date, or impair the performance of the works in use. Here's what most commercial managers miss: your <a href="/en/earned-value/definitions/earned-value-management">earned value management</a> data is generating early warning signals every month.</p> <p>A CPI dropping from 1.02 to 0.88 in two reporting periods is as measurable as it gets. This page explains how EVM metrics function as a quantitative early warning system.</p> <h2 id="what-clause-16-actually-requires">What Clause 16 Actually Requires</h2> <p>Either party can notify an early warning. You don't need certainty. You need awareness of a matter that could affect cost, time, or performance.</p> <h2 id="how-evm-metrics-work-as-early-warning-data">How EVM Metrics Work as Early Warning Data</h2> <p>A <a href="/en/earned-value/definitions/cost-performance-index">CPI</a> below 0.90 tells you the project is burning through budget 10% faster than planned. These aren't opinions. They're calculations.</p> <h2 id="worked-example-cpi-drop-on-a-15m-highways-package">Worked Example: CPI Drop on a £15M Highways Package</h2> <span class="ge-worked-label">Worked Example</span> <div class="ge-callout ge-anim"> <p><strong>Scenario:</strong> £15M highways improvement package under NEC4 Option C. At month 4, CPI drops from 1.04 to 0.86. EAC jumps from £14.4M to £17.4M.</p> <p>The risk reduction meeting agrees three actions: notify the CE, revise the methodology, update the programme.</p> </div> <h2 id="the-early-warning-register">The Early Warning Register</h2> <p>A proper early warning register should include the EVM data that triggered it.</p> <h2 id="setting-your-early-warning-thresholds">Setting Your Early Warning Thresholds</h2> <p>Recommended thresholds: CPI single-period drop greater than 0.10, cumulative CPI below 0.90, SPI below 0.90, EAC exceeding BAC+5%.</p> <h2 id="common-mistakes">Common Mistakes</h2> <ol> <li><strong>Treating early warnings as blame.</strong></li> <li><strong>Ignoring EVM trend data.</strong></li> <li><strong>Not connecting early warnings to compensation events.</strong></li> <li><strong>Vague notifications.</strong></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. <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>Is there a time limit for issuing an NEC4 early warning?</h3> <p>No. Unlike compensation event notifications, there's no contractual deadline for early warnings.</p> <h3>Can the PM reduce a CE because of a missing early warning?</h3> <p>Yes. Clause 63.7 allows the PM to assess a CE as if the Contractor had given an early warning.</p> <h3>What's the difference between an early warning and a CE notification?</h3> <p>An early warning flags a risk. A CE notification formally notifies a specific event.</p> </article> </div>