J. PourmahmoUd - Department of Applied Mathematics, Azarbaijan Shahid Madani University, Tabriz, ‎Iran.
D. Norouzi - Department of Applied Mathematics, Azarbaijan Shahid Madani University, Tabriz, Iran.

Classic Data Envelopment Analysis assumes that the values of inputs and outputs are exactly determined. However, in most real-life problems, the exact values of some of the inputs and outputs are imprecise. One of such imprecise data is ordinal data. In this paper, a new model is presented for measuring the efficiency evaluation of 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 of proposed model are compared with Cooper model. Therefore, the efficiency scores obtained from proposed model are more realistic and reasonable than the results obtained from the Cooper's model.

Evaluation, Data Envelopment Analysis, Imprecise data, Exact Data, Ordinal Data, Efficiency, Ranking