摘要

In the analytic hierarchy process (AHP), Saaty's consistency index is performed to ensure that the preference information, provided in an individual judgement matrix, is neither random nor illogical. Based on the extension of Saaty's consistency index, this paper proposes a consensus index to measure the difference between the individual preference values and the collective preference value in AHP group decision making. Furthermore, based on the consensus index, we propose a consensus prioritisation method to obtain the collective priority vector for AHP group decision making, and develop a non-linear programme model to automatically reach acceptable consensus in a local context (a unique criterion). The consensus model in this paper can optimally preserve original preference information in reaching acceptable consensus (in some sense). A genetic algorithm also is designed to solve this non-linear programme model.