Directional distance functions and slacks-based measures of efficiency

In this paper we introduce a SBM (slacks-based measure) of efficiency based on directional distance functions. This measure is contrasted with the SBM due to Professor Tone [Tone. K., 2001. A slacks-based measure of efficiency in data envelopment analysis. European journal of Operational Research 130,498-509]. (C) 2009 Elsevier B.V. All rights reserved.