Ingenieria

AACE International Recommended Practice No. 17R-97

COST ESTIMATE CLASSIFICATION SYSTEM
TCM Framework: 7.3 – Cost Estimating and Budgeting

Acknowledgments: Peter Christensen, CCE (Author) Larry R. Dysert, CCC (Author) Jennifer Bates, CCE Dorothy J. Burton Robert C. Creese, PE CCE John K. Hollmann, PE CCE
Copyright 2003 AACE, Inc.

Kenneth K. Humphreys, PE CCE Donald F. McDonald, Jr. PECCE C. Arthur Miller Bernard A. Pietlock, CCC Wesley R. Querns, CCE Don L. Short, II
AACE International Recommended Practices

AACE International Recommended Practice No. 17R-97

COST ESTIMATE CLASSIFICATION SYSTEM
TCM Framework: 7.3 – Cost Estimating and Budgeting

August 12, 1997 PURPOSE As a recommended practice of AACE International, the Cost Estimate Classification System providesguidelines for applying the general principles of estimate classification to asset project cost estimates. Asset project cost estimates typically involve estimates for capital investment, and exclude operating and life-cycle evaluations. The Cost Estimate Classification System maps the phases and stages of asset cost estimating together with a generic maturity and quality matrix that can be appliedacross a wide variety of industries. This guideline and its addenda have been developed in a way that: • • • • provides common understanding of the concepts involved with classifying project cost estimates, regardless of the type of enterprise or industry the estimates relate to; fully defines and correlates the major characteristics used in classifying cost estimates so that enterprises mayunambiguously determine how their practices compare to the guidelines; uses degree of project definition as the primary characteristic to categorize estimate classes; and reflects generally-accepted practices in the cost engineering profession.

An intent of the guidelines is to improve communication among all of the stakeholders involved with preparing, evaluating, and using project cost estimates.The various parties that use project cost estimates often misinterpret the quality and value of the information available to prepare cost estimates, the various methods employed during the estimating process, the accuracy level expected from estimates, and the level of risk associated with estimates. This classification guideline is intended to help those involved with project estimates to avoidmisinterpretation of the various classes of cost estimates and to avoid their misapplication and misrepresentation. Improving communications about estimate classifications reduces business costs and project cycle times by avoiding inappropriate business and financial decisions, actions, delays, or disputes caused by misunderstandings of cost estimates and what they are expected to represent. Thisdocument is intended to provide a guideline, not a standard. It is understood that each enterprise may have its own project and estimating processes and terminology, and may classify estimates in particular ways. This guideline provides a generic and generally-acceptable classification system that can be used as a basis to compare against. If an enterprise or organization has not yet formallydocumented its own estimate classification scheme, then this guideline may provide an acceptable starting point. INTRODUCTION An AACE International guideline for cost estimate classification for the process industries was developed in the late 1960s or early 1970s, and a simplified version was adopted as an ANSI Standard Z94.0 in 1972. Those guidelines and standards enjoy reasonably broad acceptancewithin the engineering and construction communities and within the process industries. This recommended practice guide and its addenda improves upon these standards by: 1. providing a classification method applicable across all industries; and 2. unambiguously identifying, cross-referencing, benchmarking, and empirically evaluating the multiple characteristics related to the class of cost estimate....