مشخصات پژوهش

Classic Data Envelopment Analysis expect that the values of inputs and outputs are precisely determined. However, in most real-life issues, the values of some of inputs and outputs are imprecise‎. One of them is ordinal data. In this article, a new model is presented for evaluating decision making units with ordinal data. The general idea of ​​this model is assigning real values to ordinal data with new approach. Furthermore, another new model for ranking efficient units is presented with the main idea of changes in controlled efficiency. Then, the results with results Cooper's model are compared. Therefore, the efficiency scores obtained from proposed model are more realistic and reasonable than the results obtained from the Cooper's model.