Hesitant fuzzy linguistic multiple attribute decision making

As a generalization of hesitant fuzzy set (HFS), hesitant fuzzy linguistic term set (HFLTS) deals with several values in a membership function in qualitative settings so that experts think of several possible linguistic values or richer expressions than a single term for an indicator, alternative, variable, etc. However, ranking alternatives expressed with HFLTSs and aggregating hesitant fuzzy linguistic term information are still open problems in hesitant fuzzy linguistic multiple attribute decision making (MADM) fields. Therefore, we investigate hesitant fuzzy linguistic MADM problems in this paper, particular emphasis is put on solving afore-mentioned two key open problems. Firstly, we propose an approach to solve the problem of ranking alternatives expressed with HFLTSs. Secondly, we propose four uncertain hesitant fuzzy linguistic aggregation operators. Thirdly, an approach to hesitant fuzzy linguistic MADM is developed based on the ranking approach and the proposed aggregation operators. Finally, we utilize some examples to validate the proposed decision making methods.