AACE 31R-03: The Standard for Estimate Review and Validation
AACE Recommended Practice 31R-03 defines the methodology for independent estimate reviews. We examine what it covers, why it matters and how to apply it on capital projects.
What Is AACE 31R-03?
AACE International Recommended Practice 31R-03, Estimate Review and Validation, provides a structured framework for the independent assessment of cost estimates produced for capital projects. It defines the objectives, scope, methodology and deliverables of a robust estimate review process.
The practice is applicable across all estimate classes — from Class 5 order-of-magnitude estimates through to Class 2 definitive budgets — and across all project types including process plant, infrastructure and building construction.
Why Independent Review Matters
Optimism bias is a well-documented phenomenon in capital project cost estimation. Internal estimating teams, under pressure to make a project appear viable, systematically underestimate costs and overestimate productivity. Independent review — conducted by a party with no stake in the project outcome — is the most effective mechanism for identifying and correcting this bias.
AACE 31R-03 provides the structured methodology that makes independent reviews defensible and repeatable, rather than ad hoc assessments that vary in scope and rigour from one reviewer to the next.
The 31R-03 Review Framework
The practice organises the review process into four phases:
- Scoping — Define the review objectives, estimate class, project scope and basis of estimate
- Data Collection — Gather estimate packages, scope documents, execution plan and risk register
- Analysis — Evaluate methodology, completeness, pricing basis, contingency adequacy and benchmarking against peer projects
- Reporting — Document findings, recommendations and risk-adjusted ranges
Applying 31R-03 with Kpex
CAF Corporation applies the 31R-03 framework on all estimate quality assurance engagements. The Kpex platform provides the benchmarking data — location-adjusted project costs, equipment cost curves and discipline manhour KPIs — that allow reviewers to compare the estimate under review against real executed project outcomes.
