Evaluating the Performance of Cement Companies Operating in A Stock Exchange: An Application of an Improved Fuzzy Data Envelopment Analysis (FDEA) Model
In the current study, we have introduced and developed the fuzzy Data Envelopment Analysisi (DEA) model in such a manner that it can be used for an evaluation that is more realistic and more practical. In the existing FDEA models, the model was solved by taking the optimistic and pessimistic approaches. The two approaches have various constraints to determine the performance of Decision Making Units (DMUs), which led to the adoption of different production frontiers for evaluation. If the production frontier is not unified and fixed, then the relation between the performances is meaningless. That is why we have attempted to solve this problem by using the same constraint set for each optimistic and pessimistic approach. In this article, first by using the same constraint set for the both approaches, we have gained a common production frontier, and then we have merged the optimistic and pessimistic models to create a new interval model. Finally, by using the α-cut method, we have turned it into a deterministic model. Then, by substituting variables in the model, the non-linear model was changed to a linear.
We used the developed model to measure the performance of cement companies. The efficiency that was calculated from this model was represented by the intervals; therefore, we have used the Mini-Max Regret Approach (MRA) method for ranking these interval efficiencies, 11 companies with interval efficiency (1 1) have together got the first place. We use the Anderson-Peterson Approach (AP) approach to rank these 11 companies.