GAO Cost Estimating and Assessment Guide
The US Government Accountability Office guide, GAO-20-195G, setting out the 12 steps of a reliable cost estimating process and the 4 characteristics a credible estimate must display.
Published in March 2020, replacing the 2009 edition, the guide describes estimating as a process with 12 steps, from defining the estimate’s purpose through developing the point estimate to documenting, presenting and updating it. It groups 18 best practices under 4 characteristics: a reliable estimate is comprehensive, well documented, accurate and credible, and each characteristic is testable.
Credible carries the most weight. Under the guide an estimate earns it only through cross-checking, independent review, and risk and uncertainty analysis, and the guide treats contingency as an output of that analysis at a stated confidence level rather than a percentage applied by habit.
Sources
US Government Accountability Office, Cost Estimating and Assessment Guide: Best Practices for Developing and Managing Program Costs, GAO-20-195G, March 2020: the 12 step process, 18 best practices and 4 characteristics of a reliable estimate.
Read the sources
- GAO Cost Estimating and Assessment Guide, GAO-20-195G, March 2020GAO-20-195G, March 2020; read 2026-08-24.