Serpell Bley, A F (1990) Improved conceptual estimating performance using a knowledge-based approach. PhD thesis, University of Texas at Austin, USA.
Abstract
This dissertation presents the foundations of a knowledge-based approach for improving and measuring conceptual estimating performance. Conceptual estimating is defined as the forecasting of project costs with an incomplete scope definition and before any significant amount of information is available from detailed project design. Because of these information constraints, conceptual estimating needs the contextual application of estimating expertise and judgment. This study addresses the question of how conceptual estimating knowledge and information can be acquired and used to solve specific problems of this domain in order to achieve better performance. It also demonstrates how these inputs can be used in the assessment of the expected quality of conceptual estimates. Knowledge-based Expert Systems (KBES) concepts are applied to develop a conceptual estimating architecture that integrates knowledge and expertise to emulate the performance of an experienced estimator. The study of conceptual estimating literature and a survey on estimating practices reveals that scope definition is the most critical challenge of the estimating problem and should be the real target of estimating efforts. The issues of scope definition are explored and ideas for their resolution proposed. A new scope modeling procedure is designed, and an object-oriented system is selected for scope knowledge representation. A scope modeling system prototype is implemented in a microcomputer, to demonstrate the capabilities of this approach. The problem of assessing the expected accuracy and realiability of estimates is also addressed in this research. Through conceptual analysis an accuracy causal model is developed. This model is utilized to assess estimates' accuracy and reliability using knowledge acquired from experienced estimators. A microcomputer prototype system is also designed and implemented to demonstrate this quality assessment methodology.
| Item Type: | Thesis (Doctoral) |
|---|---|
| Thesis advisor: | Ashley, David B and Borcherding, John D |
| Uncontrolled Keywords: | accuracy; liability; reliability; foundations; estimating; expert system; forecasting; project cost; estimator |
| Index terms: | survey, accuracy, project cost, quality assessment, prototype, liability, estimating, estimator, expert system, methodology, forecasting, judgment, project design, dissertation, foundations, resolution, modelling, estimate |
| Subjects: | modelling and simulation, contractual arrangements, prediction and forecasting, financial and cost management, analytical methods, profession, data collection methods, research dissemination and communication, dispute resolution, data management, conflict resolution, quality assurance, liability law, structural engineering, economics, research methods, professional development |
| Topics: | Digital Applications, Legal Issues, Quality Management, Cost Management, Engineering Principles, Information Management, Research Practice, Roles and Professions, Stakeholder Management, Procurement |
| Descriptive scope: | 5 PCTEA |
N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here