The multi-criteria group decision-making FlowSort method using the output aggregation

Real-life problems are multifaceted in nature and can create ambiguity in decision-making. Consequently, it is difficult to make the scoring criteria precise and to ultimate the exact values of attributes in multi-criteria analysis. Usually, an individual DM cannot make a judgement alone. In fact, he was unable to effectively define the opinions and the favourites of the entire team using multiple criteria, as everyone seeks to demonstrate their personal impact on the process in terms of his individual and team interests. This paper examines one of the sorting methods, named FlowSort, and extends it to multi-criteria group decision-making based on the aggregation of individual sorting result outputs. The evaluation of each alternative is described by lexical terms that can be represented by triangular intuitionistic fuzzy numbers. To validate our extension, an illustrative example and empirical comparison with other multi-criteria decision-making methods is carried out.