A Novel Trapezoidal Bipolar Fuzzy TOPSIS Method for Group Decision-Making

In this research article, the notions of bipolar fuzzy numbers, trapezoidal bipolar fuzzy numbers, triangular bipolar fuzzy numbers and bipolar fuzzy linguistic variables are introduced. Ranking function on the set of all bipolar fuzzy numbers, and the expressions for the ranking of trapezoidal and triangular bipolar fuzzy numbers are derived. A group decision making method based on trapezoidal bipolar fuzzy TOPSIS method is proposed, and the implementation of the proposed method in the selection of best project proposal is presented. Finally, a theoretical comparison of the proposed trapezoidal bipolar fuzzy TOPSIS method with other multi-criteria decision making methods such as TOPSIS, bipolar fuzzy TOPSIS and bipolar fuzzy ELECTRE I is discussed.