Cost Estimate Classifications[edit]
Common cost estimate classifications historically used are
Order of Magnitude
Preliminary
Definitive
These correspond to modern published classes 5, 3, and 1, respectively. The U.S. Department of Energy and many others use a system of five classes of estimates:
Estimate Class
Name
Purpose
Project Definition Level
Class 5 Order of Magnitude Screening or Feasibility 0% to 2%
Class 4 Intermediate Concept Study or Feasibility 1% to 15%
Class 3 Preliminary Budget, Authorization, or Control 10% to 40%
Class 2 Substantive Control or Bid/Tender 30% to 70%
Class 1 Definitive Check Estimate or Bid/Tender 50% to 100%