Supplier selection with interval type-2 fuzzy rulebased AHP (IT2 FRB AHP) approach: a new method of application  Comparison of IT2 FRB AHP and interval type 2 fuzzy AHP (IT2 FAHP) method  Ranking of alternatives with IT2 FRB AHP and IT2 FAHP approach

 Selection and sorting of environmentally friendly green suppliers  An integrated DEMATEL-QFD-AT2 BAHP method  Degree of relationship between customer demands and supplier selection criteria The aim of this paper is to put forward an integrated approach for green supplier selection by considering various environmental performance requirements and criteria. The proposed approach were addressed the interrelationships between the customer requirements (CRs) with the aid of decision-making trial and evaluation laboratory (DEMATEL) method while constructing a relationship structure. Quality function deployment (QFD) model was used to establish a central relationship matrix in order to identify degree of relationship between each pair of supplier selection criteria and CRs. Afterwards, interval type-2 fuzzy analytic hierarchy process (IT2 FAHP) applied to prioritize and rank the alternative suppliers. At the ende a case study is presented to reveal the potentiality and aptness of the proposed methodology. For the proposed integrated method (DEMATEL-QFD-IT2 AHP), the ranking of green suppliers is given in Table A. Table A. Sorting of green suppliers Defuzzified values Sorting values of green suppliers A1 Purpose: The main purpose of this study is to solve the problem of evaluation and rating of green suppliers using an integrated formulation. Theory and Methods: This study is to put forward an integrated approach for green supplier selection by considering various environmental performance requirements and criteria. The proposed approach addresses the interrelationships between the customer requirements (CRs) with the aid of decision-making trial and evaluation laboratory (DEMATEL) method while constructing a relationship structure. Quality function deployment (QFD) model was used to establish a central relationship matrix in order to identify degree of relationship between each pair of supplier selection criteria and CRs. Afterwards, interval type-2 fuzzy analytic hierarchy process (IT2 FAHP) applied to prioritize and rank the alternative suppliers. Results: This scope of work; In addition to the supplier criteria, an approach that considers the customer preferences is adopted. As a result of the proposed integrated approach, supplier rankings are listed in A3> A5> A4> A1> A8> A2> A7> A6> A10> A9. Accordingly, it is seen that the best supplier for the company is the supplier of A3 and the second supplier is the A5 supplier. A9 and A10 suppliers were the worst suppliers for the company, respectively. In addition, the demand for management commitment was calculated as the most important value among the demands of the customer requirements and it was seen that it has the maximum relationship density with other customer demands. The demand for management commitment was also the most convincing factor compared to other factors due to its highest D-R value. Therefore, the demand for management commitment in terms of customer requirements plays an important role in the supplier evaluation problem and has the greatest impac...

Fuzzy logic is a theory based on human-specific approximate reasoning. Therefore, fuzzy logic applications can bring simple and more effective solutions to situations that classical methods cannot overcome. The type-1 fuzzy set is a set, which has a continuous (crisp) membership degree to which a membership degree between 0 and 1 is assigned, and is characterised by membership functions. Type-2 fuzzy sets, which have the power to express uncertainty better, are expressed by membership functions, where the membership degrees of each element belonging to that set also specify a fuzzy set.Therefore, type-2 fuzzy sets allow us to include the membership functions uncertainty in fuzzy set theory. Using expert knowledge and using sensitivity of human to reflect the level of the decision maker influence is expressed as a fuzzy rule based system. Recently, it has been seen that fuzzy rules are frequently used together with multi-criteria decision making (MCDM) methods. Again, combining fuzzy rules with type-2 fuzzy numbers is also found. In this study, the Best Worst Method (BWM), one of the MCDM methods, has been integrated with fuzzy rules based interval type-2. The developed hybrid method was defined as Interval Type-2 Fuzzy Rule-Based BWM (IT2 FRB BWM). The proposed hybrid method has an important place when there are alternatives with similar ranking positions. Thus, even if there is a small difference in each alternative, it will show the difference better (more sensitively). This makes the proposed hybrid method forceful and unique.The proposed approach has been applied to a sustainable supplier selection problem comparatively with the BWM. The results show that the IT2 FRB BWM approach is more successful in ordering alternatives than the classical BWM method.