HKSM

An estimating approach that applies mathematical models or unit rates to historical data and specific project parameters to forecast total cost or duration.

Key Points

• Uses measurable drivers (e.g., cost per unit, hours per feature) multiplied by quantities to produce estimates.
• Depends on reliable historical data and clearly defined parameters for accuracy.
• Models can be simple linear rates or more complex algorithms with multiple variables.
• Often more accurate than analogous estimating when the scope and parameters are well understood.

Example

A construction team estimates flooring installation using a rate of $12 per square foot based on past projects. For 8,000 square feet, the cost estimate is 8,000 x $12 = $96,000. They adjust the rate by +10% for a premium material, resulting in $105,600.

PMP Example Question

Which estimating technique derives total effort by multiplying historical productivity rates by the number of units to be produced?

1. Analogous estimating
2. Parametric estimating
3. Bottom-up estimating
4. Three-point estimating

Correct Answer: B — Parametric estimating

Explanation: Parametric estimating uses historical rates or algorithms (e.g., cost or hours per unit) applied to known quantities to calculate an overall estimate.