A Fuzzy Decision Making Method in Developing Environmental Performance Index

Environmental Performance Index (EPI) is used to rank the performance in environment protection for most of the countries in the world. EPI is a score which gives a gauge at a national government scale using the method of proximity-to-target value. The current method fails to consider incomplete and vague environment data in its computations. This paper proposes a new score of EPI using a decision making method of intervalvalued intuitionistic fuzzy TOPSIS. Differently from the typical arithmetic operations of the proximity-to-target value, which directly used subtraction and division, this method introduces the concept of distance to ideal solution based on the decision makers’ assessments. A case of eleven countries in Southeast Asia region was considered to illustrate the computations. Three decision makers were invited to rate the extent of a country performs against the specific environmental criteria using the defined linguistic variables. An interval-valued intuitionistic fuzzy decision matrix was constructed based on dual degree of membership elicited from decision makers’ assessment. The closeness coefficient that represents a score for each country was finally established after executing the five-step computation. With the closeness coefficient of 0.8028, Malaysia was the best EPI among the selected countries. The method successfully offers a new score of EPI and subsequently managed to identify the countries’ environmental performance. Key-Words: Environmental assessment, intuitionistic fuzzy sets, environmental criteria, decision making, linguistic assessment