A linear programming based approach for determining maximal closest   reference set in DEA
  Identification of the reference set for each decision making unit (DMU) is a main concern in the data envelopment analysis (DEA). All of the methods developed to date have been focused on finding the furthest reference DMUs. In this paper, we introduce the new notion of maximal closest reference set (MCRS) containing the maximum number of closest reference DMUs to the assessed DMU. Then, we develop a linear programming (LP) model for determining the MCRS for each inefficient DMU. We illustrate our method through a numerical example. 
Israfil Roshdi, Mahmood Mehdiloozad, Dimitris Margaritis
math.OC