Group Decision-Making Approach without Weighted Aggregation Operators

This paper introduces an approach for group decision-making problems (GDMP) without weighted aggregation operators. This approach is more suitable for scenarios with infinite number of individuals. A mathematical model approach is established based on the new concept of -optimal concession equilibrium solution without weighted aggregation operators for group decision-making problems. It is of practical significance for all decision-makers (experts) to find an optimal solution or to sort out all the candidate solutions. We prove that the -optimal concession equilibrium solution is equivalent to solving a single objective optimization problem, and, under certain conditions, the -optimal equilibrium solution always exists. Moreover, it is proven that the -optimal concession equilibrium solution is equivalent to the robust optimal solution of the group weight aggregation and the optimal solution under the worst weighted aggregation operators.