Which estimating method uses costs based on previous similar projects?

• A. Analogous
• B. Parametric
• C. Delphi
• D. Bottom-up

Answer: (A)

Analogous estimating uses costs from a previous similar project as the basis and then adjusts for differences in size, scope, and complexity. This approach is especially useful early in a project when details are incomplete, because it relies on real-world data from comparable work to generate a quick, rough estimate. Its strength is speed and simplicity, but its accuracy depends on how truly similar the past project was and how well you account for variations such as scale, inflation, and risk.

Parametric estimating, by contrast, builds the cost from a relationship between cost drivers (like cost per unit times the number of units) and can be more precise if solid data exist. Delphi uses iterative rounds of expert judgment to converge on a consensus estimate, not directly tied to a previous project’s cost. Bottom-up estimates cost by detailing and totaling every component, which yields high accuracy but is time-consuming.