A SUPER-EFFICIENCY EVALUATION APPROACH WITHOUT INFEASIBILITY

Super-efficiency BCC model is referred to as the variable returns to scale (VRS) model, and widely used in a variety of ways. However, the super-efficiency BCC model may be infeasible for some efficient decision making units (DMUs). In order to obtain the super-efficiency, a feasible super-efficiency evaluation approach is proposed to overcome the infeasibility problem. In this work, the production vector of an activity, which is away from the production possibility set, is obtained from the constraint condition of super-efficiency BCC model. The position relationship of the production possibility set and the line segment joining the activity to the evaluated DMU is analyzed. Moreover, the number of their intersection points is equal to the number of solutions of inequalities which consist of expressions of the production possibility set and the line segment. Super-efficiency of the evaluated DMU depends upon the number of solutions. Finally, the use of the proposed approach is illustrated by means of two examples.