Contingency Reserve in EVM: Management Reserve vs Contingency

<div class="ge-article-wrapper"><article class="ge-article-body"><p>Contingency reserve is budget set aside for identified risks that may or may not materialise during the project. In formal EVM terminology, contingency sits within the <a href="/en/earned-value/definitions/performance-measurement-baseline">Performance Measurement Baseline (PMB)</a> because it's allocated to specific risk items within control accounts. This distinguishes it from <a href="/en/earned-value/definitions/management-reserve">Management Reserve</a>, which sits outside the PMB.</p><p>This term is part of the <a href="/en/earned-value/definitions">earned value definitions glossary</a>.</p><h2>Contingency vs Management Reserve</h2><pre class="ge-ascii-diagram ge-anim">EVM BUDGET STRUCTURE ┌──────────────────────────────────────┐ │ CONTRACT BUDGET BASE (CBB) │ │ │ │ ┌────────────────────────────┐ │ │ │ BAC (PMB) │ │ │ │ │ │ │ │ Work packages + │ │ │ │ CONTINGENCY RESERVE │ MR │ │ │ (identified risks) │ (unknown)│ │ └────────────────────────────┘ │ └──────────────────────────────────────┘ Contingency: INSIDE PMB (known risks, allocated) Management Reserve: OUTSIDE PMB (unknown risks, held centrally)</pre><h2>How Contingency Works on NEC4</h2><p>On NEC4 Option C, risk allowances in the target price function as contingency. When a risk materialises and becomes a compensation event, the contingency is consumed and the target adjusts. If the risk doesn't materialise, the contingency contributes to gain share.</p><h2>Worked Example</h2><span class="ge-worked-label">Worked Example</span><div class="ge-callout ge-anim"><p><strong>Scenario:</strong> A £35M NEC4 Option C infrastructure project. The target includes £2.1M of identified risk allowances (contingency) spread across 8 work packages.</p><p>At month 9, two risks materialise: ground contamination (£480K) and design coordination delay (£220K). Total: £700K.</p><p>The contingency drawdown reduces available contingency from £2.1M to £1.4M. BAC doesn't change (the budget was already in the PMB). But the cost against those packages increases, reducing CPI for those specific control accounts.</p></div><h2>Common Mistakes</h2><ol><li><strong>Putting contingency outside the PMB.</strong> That's management reserve. Contingency is allocated to specific risks within the baseline.</li><li><strong>Not tracking contingency burn-down.</strong> You need to know how much contingency remains vs how many identified risks are still open.</li><li><strong>Treating contingency as a slush fund.</strong> It's for identified risks, not for absorbing cost overruns from poor performance.</li></ol><div class="ge-product-note ge-anim"><p><strong>How Gather helps.</strong> Gather tracks risk events from your site diaries and maps them against your contingency allocation. <a href="https://gatherinsights.com/contact">Book a demo</a>.</p></div><h2>Frequently Asked Questions</h2><h3>How much contingency should a project carry?</h3><p>Typically 5-15% of BAC for UK infrastructure. The exact amount comes from the risk register and quantitative risk analysis. On NEC4 Option C, the risk allowances in the tender build-up should reflect this.</p><h3>Does using contingency change BAC?</h3><p>No. Contingency is already within BAC. Using it redistributes budget from risk allowance to actual work package costs. BAC stays the same.</p></article></div>