Parametric Estimating

Parametric Estimating is an estimating technique that uses a statistical relationship between data and other variables to calculate the estimate.

It is simply a mathematical model. The complexity of the model may vary based on the nature of the project or activity to be estimated.

For example, you could use a spreadsheet to create a simple parametric model for the following variables:

• Number of senior programmers
• Number of junior programmers
• Pay rate for senior programmers
• Pay rate for junior programmers
• Number of months
• Number of work hours in a month (160 or 173.33)

Prerequisites

• ROM Parametric estimating spreadsheet

Steps

1. Create the estimating spreadsheet
2. Populate the spreadsheet based on project assumptions
3. Revise the assumptions and update the spreadsheet to refine the estimate
4. Document estimates