s.h Razavi Hajiagha - Department of Systemic and Productivity Research, Institute for Trade Studies and Research, Tehran, Iran,
sh.s Hashemi - Department of management, Kashan Branch, Islamic Azad University, Kashan, Iran, shide
h Amoozad Mahdiraji - Department of management, Kashan Branch, Islamic Azad University, Kashan, Iran

Data envelopment analysis operates as a tool to appraise the relativeefficiency of a set of homogenous decision making units. DEA allowseach DMU to take its optimal weight in comparison to other DMUswhile a similar condition is considered for other units. This featurethreats the comparability of different units because different weightingschemes are used for different DMUs. In this paper, a model ispresented to determine a common set of weights to calculate DMUsefficiency. This model is developed based on a multi objectivefractional linear programming model that considers the originalDEA's results as ideal solution and seeks a set of common weights toevaluate DMUs and increases the model's discrimination power. Anumerical example is solved and the proposed method's results arecompared to some previous methods. This Comparison has shown theproposed method's advantages in ranking DMUs.

DEA, Common Set of Weights,Multi Objective FractionalLinear Programming,Membership Function,Ranking