Decision-making method based on an improved similarity measure between vague sets

Aimed at a generalization of the concept of fuzzy sets—vague sets that involve three dimension meaning (certainty, negation, and uncertainty) in a vague set, an improved mean similarity measure between vague sets and its decision-making method are presented when the influence of uncertain degree (hesitancy degree) on certain degree and negative degree were considered in similarity measures between vague sets. The improved similarity measure between vague sets illustrates by comparison with previous mean similarity measures that it had stronger discrimination. While the decision-making problem of engineering alternatives is being made, the similarity measure between vague sets is the measure for evaluating whether an engineering alternative is close to the expected scheme (ideal scheme) or not. The bigger the value of similarity measure is, the better the close degree between the engineering alternative and the expected scheme is. It has been expounded through an example that the application of the similarity measure analysis between vague sets to the decision-making of engineering alternatives is feasible. The presented decision-making method will give decision makers the theoretical warranty in the selection of the optimal alternative.