A Review on Ranking of Z-numbers

There are numerous studies about Z-numbers since its inception in 2011. Because Z-number concept reflects human ability to make rational decisions, Z-number based multi-criteria decision making problems are one of these studies. When the problem is translated from linguistic information into Z-number domain, the important question occurs that which Z-number should be selected. To answer this question, several ranking methods have been proposed. To compare the performances of these methods, benchmark set of fuzzy Z-numbers has been created in time. There are relatively new methods that their performances are not examined yet on this benchmark problem. In this paper, we worked on these studies which are relative entropy based Z-number ranking method and a method for ranking discrete Z-numbers. The authors tried to examine their performances on the benchmark problem and compared the results with the other ranking algorithms. The results are consistent with the literature, mostly. The advantages and the drawbacks of the methods are presented which can be useful for the researchers who are interested in this area