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Cost Estimation
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Cost Estimate Classification System - As Applied in Engineering, Procurement, and Construction for the Nuclear Power Industries

Cost Estimate Classification System - As Applied in Engineering,Procurement, and Construction for the Nuclear Power Industries, AACE International, Recommended Practice No. 115R-21, AACE International, Morgantown, WV, (Rev. 2022/02/05)

As a recommended practice (RP) of AACE International, the Cost Estimate Classification System provides guidelines for applying the general principles of estimate classification to nuclear new build and modification project cost estimates (i.e., cost estimates that are used to evaluate, approve, and/or fund projects). The Cost Estimate Classification System maps the phases and stages of project cost estimating together into a generic project scope definition maturity and quality matrix, which can be applied across the nuclear power plant industry.

This recommended practice provides guidelines to both owners and service providers for applying the principles of estimate classification specifically to project estimates for engineering, procurement, and construction (EPC) or other contractual arrangements and execution venues, and their related work in ongoing or developing nuclear power related projects. It supplements the generic cost estimate classification RP 17R-97 by providing:

  • A section that further defines classification concepts as they apply to the nuclear power industry and their unique differences to other industries.
  • A section on the industry specific quality assurance and regulatory requirements that might influence the cost estimate.
  • A section on general guidance regarding the application of productivity factors applicable to labor quantification that are specific to the conduct of work in support of nuclear power projects.
  • A chart that maps the extent and maturity of estimate input information (for example, project definition deliverables) into the estimate class.

As with the generic RP, the intent of this document is to improve communications and consensus among all the stakeholders involved with preparing, evaluating, and using project cost estimates specifically for the nuclear power industries.

The overall purpose of this recommended practice is to provide the nuclear power industries with a project definition deliverable maturity matrix that is not covered in RP 17R-97. It also provides an approximate representation of the relationship of planning, preparation, design input data and project scope deliverable maturity with the estimate accuracy and methodology used to produce the cost estimate.

This document is intended to provide a guideline, not a standard. It is understood that each enterprise may have its own project and estimating processes, terminology, and may classify estimates in their own particular way. This guideline provides a generic and generally acceptable classification system for the nuclear power industries that can be used as a starting point for the basis of comparison. This recommended practice should allow each user to better assess, define, and communicate their established and developed procedures in light of generally accepted cost engineering practice.


Arnaldo M. Angelini, PE CCP (Primary Contributor)

Shoshanna Fraizinger, CCP (Primary Contributor)

Dr. Geoffrey S. Rothwell (Primary Contributor)

Apostolos Chatzisymeon

John K. Hollmann, PE CCP CEP DRMP FAACE Hon. Life

Dr. Dan Melamed, CCP EVP FAACE


Calvin Speight, Jr. CCP