Using Robust Statistical Methodology to Evaluate the Cost Performance of Project Delivery Systems: A Case Study of Horizontal Construction

Abstract

The objective of this study is to demonstrate the application of the bootstrapping M-estimator (a robust analysis of variance [ANOVA]) to test the null hypothesis of means equality among the cost performance of the three project delivery systems (PDS). A statistical planned contrast methodology is utilized after the robust ANOVA analysis to further determine where the differences of the means lie. The results of this research concluded that traditional PDS (Design-Bid-Build [DBB]) outperformed the two innovative PDS (Design-Build [DB] and Construction Manager/General Contractor [CMGC]), DBB and CMGC outperformed DB, and DBB outperformed CMGC, for the Cost Growth and the Change Order Cost Factor performance. These findings can help decision makers/owners make an informed decision regarding cost related aspects when choosing PDS for their projects. Though the case study of this research is based on the sample data obtained from the construction industry, the same methodology and statistical process can be applied to other industries and factors/variables of interest when the study sample data are unbalanced and the normality and homogeneity of variance assumptions are violated.

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Notes on contributors

Dares Charoenphol

Dares Charoenphol is a licensed professional engineer in the State of California, Virginia, and District of Columbia. She received her doctorate in Systems Engineering from the George Washington University, a master’s degree in Engineering from the University of Virginia and an M.B.A. from St. Louis University. She earned a B.S. in Business Administration from Kansas State University, and a B.S. in Engineering from the University of Texas (El Paso). She is a member of the Tau Beta Pi (Engineering Honor Society), and served as President of the District of Columbia Society of Professional Engineers in 2013–2014. Dares is a member of Defense Acquisition Corps, and is certified (at Level III) in the Program Management. She also earned certificates in the Program and the Project Management from the George Washington University.

Steven M. F. Stuban

Steven M. F. Stuban, Ph.D., P.E., is Deputy Director of the National Geospatial-Intelligence Agency’s Facility Program Office. He is a professional engineer and is Defense Acquisition Workforce Improvement Act Level III certified in the Program Management, Program Systems Engineer and Facilities Engineering career fields. He has a bachelor’s degree in Engineering from the U.S. Military Academy, a master’s degree in Engineering Management from the University of Missouri-Rolla, and both a master’s degree and a doctorate in Systems Engineering from George Washington University. Dr. Stuban is Adjunct Professor with the George Washington University and serves on a standing doctoral committee.

Jason R. Dever

Jason R. Dever, Ph.D., works as a Systems Engineer supporting the National Reconnaissance Office, responsible for developing an open IT framework such that software components can be shared across the government. In previous posts, Jason supported numerous positions across the systems engineering lifecycle, including requirements, design, development, deployment, and O&M. Jason received his bachelor’s degree in Electrical Engineering from Virginia Tech, master’s degree in Engineering Management from George Washington University, and Ph.D. in Systems Engineering from George Washington University. His teaching interests are project management, systems engineering, and quality control.