MULTI-CRITERIA EVALUATION OF THE BIDS IN PUBLIC CONSTRUCTION

misbe2011 Tracking Number 185

One of the main tasks of local and national Governments is giving the people the public facilities they need. Carrying out such activity can involve many problems, because of the amount of money required in such projects and the relevant number of involved stakeholders. In particular, a public sponsor needs to find a private firm able to build these infrastructures with the best compromise among the required resources (money, time...) and the quality of the work (in terms of, for instance, service level, technical features...). Consequently, multi-criteria evaluation schemes are often and often used by tendering committees for this kind of public works. Reaching this goal is made more difficult all over the world by attemps of corruption of the public officiers made by some competitors. In most of the States of the world, appropriate laws prescribe transparent procedures in order to avoid such events, which can determine a huge economical detritement to Governments. The European Union Public Procurement Directive 2004/18/EC imposes the use of the Linear Weighting technique (when it is possible) in public tenders to be awarded according to the Most Economically Advantageous Tender criterion. In this case, the committee has to decide the weights of each criterion in advance at the request of tender. Generally these are drawn on the basis of subjective judgments. This makes the method affected by internal consistency and validity problems. Consequently, there isn’t an absolutely optimal choice of weights. Moreover, when this awarding mechanism is used, public officers can give an advantage to a given bidder simply by assigning a high weight to a criterion that only that competitor is expected to fully meet.Consequently, this method is characterized by some subjective choices which makes corrupted behaviours possible. In the last years the literature about this issue presented many models for the evaluations of bids in public tenders. Some of these were proposed specifically for public works of construction, while other ones are more generic but can be successfully implemented also for the evaluation of the bids for the building of a facility. Among these methods, some aim at the optimal choice of the weights for the Linear Weighting. Other ones are based on the qualitative comparison among alternatives. Another group of method is based on the estimation of the utility coming from each bid. Finally, another possible approach aims at determining a sort of social cost coming from the completion time and from the quality of the final work to be summed up to the required bid. The purpose of this paper is to make a classification of different bidding mechanisms for public construction projects proposed by the literature. The strenghtens and the weaknesses of each of them are illustrated. Such an analysis aims at giving Government and public firm advice on what tendering mechanism best meet its requirements, needs and expectations in the evaluation of the bids.