Bid evaluation is the process of selecting a contractor from a number of bidders. The decision analysis models currently in use at the Portuguese Electric Transmission Company (REN) to evaluate bids were developed through a decision-conferencing process supported by the MACBETH multicriteria approach and software. This paper presents the various components of this interactive sociotechnical process. Given the number of contracts awarded by REN each year, it was crucial that the models be reusable in similar calls for tenders; this required substantial care in structuring the criteria, with a focus on constructed scales, and building value function models based on qualitative pairwise comparison judgments of difference in attractiveness. Also of particular interest is the approach for weighing benefits against costs.
