Input estimation and identification of extra inputs in inverse DEA models

In this paper we show that the inverse data envelopment analysis (DEA) models can be used to estimate inputs for a decision making unit (DMU) when some or all outputs and efficiency level of this DMU are increased or preserved. An approach is also introduced to identify extra inputs (maximum reduction amounts in inputs) when the outputs are estimated using the proposed models by Yan et al. [European Journal of Operational Research 136 (2002) 19] and Jahanshahloo et al. [Applied Mathematics and Computation 19 (2003)]. Numeric results are presented for an example taken from the literature. (C) 2003 Elsevier Inc. All rights reserved.