Sensitivity to criteria weighting in an MCDM problem of water resources planning

Multicriteria Decision Making techniques are here applied to establish the volume of a reservoir to be held by a dam, as well as other facilities needed by the several uses of the water to be delivered. The water system is simulated as if a dam and all other facilities were there, allowing the construction of basic scenarios as initial solutions to the problem. The criteria are established, the respective weights chosen and utility functions are built for each use of the water and each criterion. An additive weighted aggregation of utilities leads to an evaluation of the performance of any solution. Searching for an efficient solution with a better performance is achieved by means of a piecewise linear problem with mixed variables, solved as a bilevel problem. A systematic analysis of these better solutions is done according to the weights assigned to each criterion and indication is provided about the sensitivity of the problem to the weighting policy and about more robust combinations of solutions before weighting subjectivity.