3. Hesitant Fuzzy Multiple Criteria Decision Analysis Based on QUALIFLEX

The QUALIFLEX is a very useful outranking method to deal simultaneously with the cardinal and ordinal information in decision making process. The purpose of this chapter is to develop the hesitant fuzzy QUALIFLEX with a signed distance-based comparison method for handling MCDM problems in which both the assessments of alternatives on criteria and the weights of criteria are expressed by HFEs. In this chapter, we propose the novel concept of hesitancy index for the HFE to measure the degree of hesitancy of the decision-maker or the decision organization. By taking their hesitancy indices into account, we present a signed distance-based ranking method to compare the magnitude of HFEs. By adopting such a comparison approach, the hesitant fuzzy QUALIFLEX technique is developed. Compared with the hesitant fuzzy ELECTRE method, to handle the MCDM problems where the number of criteria markedly exceeds the number of alternatives the developed technique does not require the complicated computation procedures but still yields a reasonable and credible solution. Finally, the developed technique is extended to manage the heterogeneous information including real numbers, interval numbers, TFNs, IFNs, and HFEs.