Check Estimates (AACE Class 1), often referred to as definitive estimates, are prepared during the execution phase of a project and are typically an update of the previously completed control estimate. The updated estimate is often referred to as the current control estimate and becomes the new baseline for cost/schedule control of the project. Check estimates may be prepared for parts of the project to evaluate bids, to support vendor/contractor negotiations, or for claim evaluations and dispute resolution.
Check Estimates involve the highest degree of deterministic estimating methods. They are prepared in great detail, and thus are usually performed on only the most important or critical areas of the project. All items in the estimate are usually unit cost line items based on actual design quantities. Typical accuracy ranges for definitive estimates are between -3% to -10% on the low side and +3% to +15% on the high side, depending on the level of engineering and procurement status.