Improving qualifications-based selection by use of the fuzzy Delphi method

Abstract

Among prevailing contract-awarding paradigms, the qualifications-based selection (QBS) method offers awarding agencies a substantial level of flexibility and multifactored decision-making capability over traditional cost-based paradigms (such as competitive bidding). QBS is a process used by owners to select proposers to whom they can award a project contract, based on the proposers' professional qualifications in relation to the specific project parameters. Further to being very suitable for the selection of professional engineering design services, QBS can also be applied for the selection of contractors involved in specialized construction or design-build projects. In such cases, the procurement method and the selection criteria used are critical decisions involving several key project team members and decision factors, the formulation of which requires complex evaluation methodologies. Within this context, a process is proposed by which the traditional QBS method can be improved via the utilization of a fuzzy Delphi method (FDM), a cross-mutation of the traditional Delphi method (DM) and fuzzy logic (FL). The method utilizes 'expert' appraisals to identify both the factors and their weights in the overall evaluation process through a 'fuzzy attractiveness ratio' (FAR) which is used for evaluating the bidders' suitability to task.