## 4 Case Study
### MCDM Method Steps  
The application of MCDM methods was carried out by using the SWARA method to determine the weights of the criteria, while the CORASO method was used to determine the ranking of suppliers. To implement this, DMs must first assess the importance of the criteria and evaluate the alternatives with the selected criteria. The process of applying this research with the selected methods is presented in Figure 2.  
The importance of the criteria was determined using the SWARA method. This method is one of the subjective methods that are subject to subjective assessment by the DM. In addition to these methods, objective methods are also used in practice to determine the importance of criteria. The specificity of these objective methods is that the weight of the criteria is determined in the same way as the alternative ratings. If the ratings of alternatives to a certain criterion vary more in relation to other criteria, its importance will be greater. In  
Figure 2: MCDM method steps. objective methods, the weight of the criteria is affected by the rating of the alternative and not the importance of that criterion to the DM. This makes it possible for a criterion that is not important for the decision, according to the DM, to receive the highest importance and one that is significant to have the lowest importance. For this reason, objective methods were not used in this research to determine the importance of criteria, and a subjective method was used instead, namely, the SWARA method. However, it was possible to use a combination of objective and subjective methods to determine the weights, but even then, the objective methods would have a significant influence on the final ranking, so this idea was rejected. This method has been used in practice since 2010 [56], so it has been used in many papers and its validity has been proven in practice. In order to determine how important individual criteria are for supplier selection, an adapted SWARA method was used. The SWARA method was first used by [PERSON] et al. [56]. This is one of the methods for subjectively determining the weight of criteria [57]. The importance of weights is determined based on DM ratings. The application of this method in this research is performed as follows:  
Step 1. Assessment of the importance of criteria by the DM. In this step, DMs provide ratings in the form of linguistic terms (Table 2). Step 2. Transformation of linguistic terms and application of intuitionistic fuzzy approach definitions to form crisp values. Step 3. Harmonization of criterion ratings using the Bonferroni mean operator. \[r_{j}=\left(\frac{1}{k(k-1)}\underset{i,j=1}{\sum}\underset{i,j=1}{\sum} \underset{i}{\sum}\underset{j=1}{\overset{=(UL)p=(UL)q}{n_{i}}}\right)^{\frac{ 1}{p+q}}, \tag{13}\]  
Step 4. Ranking the average scores of the criteria. Step 5. Determining the relative importance of the criteria. The criterion with the highest average score is given a value of one (1). The other criterion values are obtained by subtracting the value of the criterion for which the relative importance of the criterion is calculated from the average value of the better ranked criterion and adding a value of one (1). \[k_{j}=\left\{ \begin{aligned} & 1\;if\;j=1\\ & s_{j}+1\;if\;j>1\end{aligned} \right. \tag{14}\]  
Step 6. Determination of relative \(q_{j}\) value. This is performed in such a way that the value one (1) is rewritten for the first ranked criterion, while \(q_{j}\), the value of the other criteria, is calculated in such a way that, from the \(q_{j}\) value, we can determine the relative importance of that criterion that counts. \[q_{j}=\left\{ \begin{aligned} & 1\;if\;j=1\\ &\frac{q_{j-1}}{k_{j}}\;if\;j>1\end{aligned} \right. \tag{15}\]  
Step 7. Calculation of criteria weights. In this step, the individual value \(q_{j}\) is divided by the cumulative \(q_{j}\) value. \[w_{j}=\frac{q_{j}}{\sum_{j=1}^{n}q_{k}}. \tag{16}\]  
After the weights of the criteria were determined, the suppliers were ranked. In this study, the CORASO method was applied.