planning phase to the next, improving the accuracy of the estimate. This research paper will project, and ends with class 1, which is an estimate developed when over 60 percent of the engineering has been complete and uses much more detailed methods of estimating. Figure 1 class 1 estimate accuracy A Project Budgetary Cost Estimate (Class 3) is a project cost estimate process similarly defined by the AACE as the Class 3 Estimate, or Budget Authorization or Control. The project Budgetary Estimate methodology is semidetailed unit costs with assembly level line items, and the expected accuracy is
The accuracy of the cost estimate will vary greatly depending on the degree of information available on the project, and the level of skill and knowledge of building costs of the estimator. class 1 estimate accuracy
Definitive Estimates (Class 1) Profit is cost to the buyer, but is not a cost to the provider, rather a projection of anticipated income. A well documented cost estimate includes a Basis of Estimate (BOE), which describes the scope basis, pricing basis, methods, assumptions, inclusions, and exclusions. Guide to Cost Predictability in Construction: An Analysis of Issues Affecting the Accuracy of Construction Cost Estimates November 2012. 13. Class D Estimate. A Class D estimate is generally an estimate based on the initial functional program and broad concept approach. Figure 1, As Estimated (and Target) Accuracy Vs. Accuracy is a measure of how a cost estimate will differ from the final actual outcome. It is also a measure of cost uncertainty or risk (these terms are essentially synonymous in TCM). Empirical estimate accuracy class 1 estimate accuracy How can the answer be improved? At an 80 percent confidence level, estimate accuracy is still bounded by the values of 0. 8 million and 1. 4 million. However, when expressed as a percentage around the point estimate including contingency (1. 1 million), the accuracy range is now 27 percent to 27 percent. Expected Accuracy Range. Typical accuracy ranges for Class 5 estimates are 20 to 50 on the low side, and 30 to 100 on the high side, depending on the technological complexity of the project, appropriate reference information and other risks ( after inclusion of an B. Estimate Classification. The Capacity Factored Estimate is derived from the cost of a similar plant of a different capacity, through the use of an appropriate exponential factor, parametric models, judgment, or analogy, and expected accuracy is Low: 20 to 50, High: 30 to 100.