AACE CEP Method Selection and Input Quality

Estimating method selection is an evidence decision. A method is strong only when it fits the purpose, scope maturity, available data, project type, and decision risk.

Matching method to situation

High-level methods are useful when information is limited. Analogous estimating uses similarity to prior work. Parametric estimating uses measurable relationships, such as cost per unit. Factored methods apply ratios or factors to major equipment or capacity. Detailed methods use quantities, labor, materials, equipment, subcontractors, indirects, and pricing inputs.

The exam trap is assuming the most detailed method is always best. A detailed estimate built from weak quantities, outdated pricing, or unrealistic productivity can be less defensible than a simpler method with transparent assumptions.

Input quality

Input quality should be tested before the estimate is trusted. Key checks include:

• source and date of pricing
• completeness of quantity takeoff
• labor productivity basis
• location and market adjustments
• currency and escalation assumptions
• vendor quote validity and exclusions
• treatment of indirect costs and taxes
• consistency with schedule and execution strategy

Reconciliation

When multiple methods are available, reconciliation is part of professional estimating. A parametric result, vendor quote, and bottom-up estimate may not match. The estimator should explain why, investigate material differences, and choose or blend methods based on reliability.

Sample Exam Question

A project team has a vendor quote that is six months old, a recent parametric benchmark, and an incomplete quantity takeoff. Which action is strongest?

A. Use the old vendor quote because vendor numbers are always more reliable.
B. Use the incomplete quantity takeoff because detailed estimates are always best.
C. Reconcile the sources, test date and scope basis, adjust where justified, and disclose the reliability of the selected method.
D. Average all three inputs without explanation.

Best answer: C

Why: Input quality and reconciliation matter more than blindly preferring one source type. The estimate should explain why the selected input is reliable for the decision.

Why the others are weaker: A ignores quote age and exclusions. B confuses detail with reliability. D hides differences instead of resolving them.