Study On The Multi-criteria Decision Making Method Based On Hesitant Fuzzy Linguistic Term Set

With the rapid development of economy, economic situation changes ever fast and the competition between companies becomes more and more fierce, thus leading to increasingly complex decision making problems. The complexity of the decision making problems and the cognitive limitations of individuals hinder decision makers (DMs) making accurate judgments in the decision-making process. Employing fuzzy number, which was proposed by Zadeh, to represent the decision-making information is an effective solution. Hesitant fuzzy number is the latest extension form of fuzzy number, featuring in its membership, which is not a certain value or obeys a certain distribution, but several possible values. Hesitant fuzzy number is much closer to the real situation, and has unique advantage in dealing with group decision making problems, which can avoid loss of information caused by aggregation operators effectively, so it appeals to many scholars’attention.Hesitant fuzzy linguistic term set (HFLTS) is a branch of research on hesitant fuzzy set and currently there are few researches on it. In this paper, HFLTS and the corresponding fuzzy multi-criteria decision-making (MCDM) methods are studied based on hesitant fuzzy set and fuzzy linguistic term set. The main achievements are as follows:(1) Given the advantages of2-tuple in processing linguistic information, hesitant fuzzy2-tuple linguistic term set (HF2TLS) and its relevant theorems and properties are defined, based on which, Context-free grammar methods and conversion functions EGH are improved to help convert the linguistic evaluation information into hesitant fuzzy2-tuple linguistic term set. Meanwhile, the score function and distance formula of HF2TLS are put forward and PROMETHEEΠ method is improved. On the basis of these, we propose hesitant fuzzy linguistic MCDM methods, in which the criteria are both known and unknown.(2) Considering that trapezoidal interval type-2fuzzy number can describe the linguistic evaluation information more accurately, trapezoidal interval type-2hesitant fuzzy number is defined to handle hesitant fuzzy linguistic information. Then from the prospective of geometrical property, its possibility degree and distance formula are proposed, besides, a new model for determining criteria weights is defined, involving DMs’ preferences. On the basis of these, we propose hesitant fuzzy linguistic MCDM methods, in which the criteria are both known and unknown.(3) The HFLTS MCDM methods are proposed in group decision making environment based on evidence reasoning, which conquer the problems of ignoring the impact of DMs’ weights and repeating values. Meanwhile, a new model for determining DMs’ weights is defined, considering fully DMs’ knowledge and experience. On the basis of these, we propose hesitant fuzzy linguistic MCDM methods, in which the criteria are both known and unknown.1figure,18tables and91references...