Contractor selection using the multiattribute utility theory
Literature and past research suggests that one of the reasons for the poor performance of the construction industry is due to the inappropriateness of the awarded contractor. In order to ensure a successful completion of a project, a comprehensive and careful assessment of contractors data in a prequalification stage is required. Appointing an appropriate contractor to carry out the construction work, therefore, becomes one of the most important tasks to ensure the success of a project. In this thesis the author has made a preliminary survey to investigate the bidding process currently used in the construction industry through literature survey, extensive interviews with the construction professionals and an industry wide questionnaire. The investigation has focused on the procedures of prequalification and bids evaluation, it also covers the list of criteria considered for selecting contractors in prequalification and bid evaluation stages. The thesis investigated the perceived relationship between contractor selection criteria (CSC) currently in use and predominant project success factors (PSF) in terms of time, cost and quality involving a sample of experienced construction professionals. This research is based on the premise that selection should concentrate on determining contractor potential for achieving project goals in terms of time, cost and quality. The study presented a quantitative technique to combine the contractor data in terms of these goals. The study also presented an evaluation strategy that involves the consideration both of the client goals as ends and contractor data as the means, the strategy based on the rnultiattribute utility theory for the frnal selection or rank ordering of the contractors. The selection is ultimately based on the preferences and the attitude of the decision maker toward risk. A real case study was used to validate the proposed methodology for contractor prequalification. The benefit of this work is that it provides a means using the PERT methodology to incorporate uncertainty andlor imprecision associated with the assessment of contractors data, this all in terms of the ultimate project success factors of time, cost, and quality. The utility technique proposed should help clients in selecting contractors and the contractors themselves for selecting sub-contractors in offering a means of broadening their analysis of tenderers beyond that of simply relying on tender values. It also alerts contractors to the importance of increasing their ability to satisfy the needs of the clients in terms of their ultimate project goals.