Using appropriate data in decision-making problems is important to achieve better results. Since having the unpredictability information of the data to be utilized will increase the validity of the solution, the fuzzy set theory has had a serious effect on decision making methods. Therefore, we handle TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) which is one of MCDM (Multiple Criteria Decision Making) methods by using fuzzy sets. Although working with type-1 fuzzy sets is more difficult than crisp numbers, it can be counted easily enough. However, they are not good enough to process unknown materials. This deficiency led to the emergence of a more competent concept in the literature. Type-2 fuzzy sets that are a special form of fuzzy sets can reflect uncertainty much better than type-1 fuzzy sets. However, the processing density of these sets has made their use quite difficult. In order to alleviate the operations, interval type-2 fuzzy sets have been developed, and these sets have been used widely in MCDM methods. Hence, interval type-2 fuzzy set theory is addressed to overcome uncertainty more realistically in our study. We adapt the previous work done on risk assessment with type-1 fuzzy sets to interval type-2 fuzzy sets by using TOPSIS. The aim of this study is to observe results by considering these works.
Anahtar Kelimeler: TOPSIS, Interval Type-2 Fuzzy Sets, Risk Assessment