A multicriteria model for assigning new orders to service suppliers

This paper describes a multicriteria model developed to support decisions on the assignment of new orders to service suppliers – in this case, contractors for the construction (or renewal) of pipeline networks for gas distribution. The model comprises two phases: (i) computation of a quota (expressed as a percentage of total work orders budget) for each supplier; (ii) assignment of each particular order to a supplier selected on the basis of a ‘multi-attribute preference index’ evaluated for each candidate contractor. The first phase is executed at the beginning of each year (and then reviewed quarterly) and the quotas are defined by a two-criteria model: the prices quoted by the supplier for standard works and the past performance of the constructor given by a performance appraisal system. The paper describes the structuring phase of the model, as well as the descriptors and corresponding partial value functions used in each stage to perform the evaluation within an additive aggregation framework.