A LINEAR MODEL FOR PERFORMANCE EVALUATION OF DECISION MAKING UNITS WITH DEA AND COMMON WEIGHTS APPROACH CASE STUDY: PHARMACEUTICAL COMPANIES IN TEHRAN

Performance evaluation is one of the most significant issues in management taken into consideration by a number of academics and researchers who have developed various parametric and non-parametric methods used for performance measurement and evaluation. Among these models, Data Envelopment Analysis (DEA) is regarded as one of the most widely used models for performance evaluation. DEA is a powerful mathematical tool and a non-parametric technique to measure the relative efficiency of a group of homogeneous Decision-Making Units (DMUs). This approach carried out an evaluation by assigning weights to the inputs and outputs of each decision-making unit. The difference in the input and output weights in this technique is one of the objections to this method that threatens the assessment of the underlying basis. In this study, a model was presented to find a solution to this problem. The proposed model is a one-phase linear model and has less computational complexity than other models. To validate this model, the numerical exam of Kao & Hung (2005) was implemented and the results of the presented model were compared with those of other models; in addition, the Spearman correlation coefficient was calculated. The results showed that the proposed model had a more significant correlation coefficient than other models, had a more resolution than other models, and eliminated the shortcomings of Classic base models. After the validation of the model, the pharmaceutical companies in Tehran Stock Exchange were evaluated by means of the proposed model and CCR model. The indices of the study were obtained from previous studies and the opinions of experts were taken into account to confirm these indices. The data used in the present study and the actual values of these indices were obtained from ``codal.ir website'' according to each company's financial status. Moreover, sensitivity analysis was performed on the outputs of these companies. The results showed that Alborz Pharmaceutical and Shafa Pharmaceutical Investment companies were the most effective units in both models, and Farabi Pharmaceutical Company was the most inefficient one. Besides, the results indicated that the units under study showed more sensitivity than the first output.