Operational Research, v. 22, n. 4, pp. 3373-3410. Abstract: In this paper we present a new model combining the major underlying ideas behind the Slacks-Based Measure (SBM) and the Data Envelopment Analysis-Ratio based (DEA-R) models. This new proposed model computes efficiency and super-efficiency scores based on the corresponding slack values for both input/output and output/input ratios, depending upon the orientation of the production frontier. A comprehensive step-by-step derivation of the SBM-DEA-R model in light of previous approaches is offered to readers. Besides, in order to show the validity of the approach proposed in light of the current body of literature, we revisit a case study of twenty-one medical centers in Taiwan. Limitations and directions for future research are discussed.
Keywords: DEA, SBM, Ratio data, Efficiency, Super-efficiency.