Quantitative Methods for Design-Build Team Selection Mounir El Asmar 1 ; Wafik Lotfallah 2 ; Gary Whited, M.ASCE 3 ; and Awad S. Hanna, F.ASCE 4 Abstract: The use of design/build DB contracting by transportation agencies has been steadily increasing as a project delivery system for large complex highway projects. However, moving to DB from traditional design-bid-build procurement can be a challenge. One significant barrier is gaining acceptance of a best-value selection process in which technical aspects of a proposal are considered separately and then combined with price to determine the winning proposal. These technical aspects mostly consist of qualitative criteria, thus making room for human errors or biases. Any perceived presence of bias or influence in the selection process can lead to public mistrust and protests by bidders. It is important that a rigorous quantitative mathematical analysis of the evaluation process be conducted to determine whether bias exists and to eliminate it. The paper discusses two potential sources of bias—evaluators and weighting model—in the DB selection process and presents mathematical models to detect and remove biases should they exist. A score normal- ization model deals with biases from the evaluators; then a graphical weight-space volume model and a Monte Carlo statistical sampling model are developed to remove biases from the weighting model. The models are then tested and demonstrated using results from the DB bridge replacement project for the collapsed Mississippi River bridge of Interstate 35W in Minneapolis. DOI: 10.1061/ASCECO.1943-7862.0000194 CE Database subject headings: Monte Carlo method; Design/build; Selection; Quantitative analysis; Bids; Construction industry. Author keywords: Monte Carlo method; Design/build; Selection; Quantitative analysis. Introduction The use of design/build DB contracting by transportation agen- cies has been steadily increasing over the last decade and is be- coming more popular as a project delivery system for large complex highway projects Gransberg and Molenaar 2003; Con- tract Administration 2002. Transportation agencies are finding that the use of DB contracting can reduce the overall project delivery time with little impact on quality. However, moving to DB from the traditional design-bid-build DBB procurement can be a challenge. There are many actual and perceived barriers that must be overcome by both the owner agencies and the contracting community. One significant barrier can be getting a buy-in on the use of a best-value selection process with DB rather than the customary low-bid selection with DBB. Public sector transportation projects tend to use selection methods in which technical aspects of the proposal are considered separately from the price component. The technical scores and price are then combined in some simple manner to determine the best value and the winning proposal Herbsman and Ellis 1992. Technical scores are determined by a technical evaluation team on the basis of prestated criteria. The absence of a quantitative meth- odology for the technical evaluation, and the potential for bias or political influence to enter the process, have caused some of the greatest concern. Any perceived presence of bias or influence in the selection process can lead to public mistrust and protests by bidders Shane et al. 2006. The case study presented in this paper described a project where the DB team selection and subsequent protest resulted in a great deal of public commentary and concern over the process. The following quotation from Engineering News Record describes the perceived presence of bias: “Two teams bidding on a replacement to the fallen I-35W bridge in Minneapolis have filed an administrative protest questioning the legality of Minnesota’s design-build procedures for highway con- struction. The move also calls into question the subjectivity of best-value procurement models” ENR, September 24, 2007. Bias in the selection process can come from individual evalu- ators or from weighting criteria, and it can be difficult to detect by simply looking at the results. It is important that a more rig- orous mathematical analysis of the evaluation process be con- ducted to determine whether bias exists and to eliminate it in order to have a fair and open selection process. Transportation agencies, the construction industry, and the public would have greater confidence in the DB best-value approach if the selection 1 Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Univ. of Wisconsin—Madison, 2256 Engineering Hall, 1415 Engineering Dr., Madison, WI 53706 corresponding author. E-mail: elasmar@ wisc.edu 2 Associate Professor, Dept. of Mathematics and Actuarial Science, American Univ. in Cairo, Egypt; and, Visiting Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Wisconsin—Madison, 2208 Engineering Hall, 1415 Engineering Dr., Madison, WI 53706. E-mail: lotfalla@math.wisc.edu 3 Program Manager, Construction and Materials Support Center, Dept. of Civil and Environmental Engineering, Univ. of Wisconsin—Madison, 2314 Engineering Hall, 1415 Engineering Dr., Madison, WI 53706. E-mail: whited@engr.wisc.edu 4 Professor and Chair, Construction Engineering and Management Program, Dept. of Civil and Environmental Engineering, Univ. of Wisconsin—Madison, 2320 Engineering Hall, 1415 Engineering Dr., Madison, WI 53706. E-mail: hanna@engr.wisc.edu Note. This manuscript was submitted on December 12, 2008; ap- proved on January 25, 2010; published online on January 28, 2010. Dis- cussion period open until January 1, 2011; separate discussions must be submitted for individual papers. This paper is part of the Journal of Construction Engineering and Management, Vol. 136, No. 8, August 1, 2010. ©ASCE, ISSN 0733-9364/2010/8-904–912/$25.00. 904 / JOURNAL OF CONSTRUCTION ENGINEERING AND MANAGEMENT © ASCE / AUGUST 2010 J. Constr. Eng. Manage. 2010.136:904-912. Downloaded from ascelibrary.org by University of Wisconsin - Madison on 05/22/13. Copyright ASCE. For personal use only; all rights reserved.