Document Type : Research Paper
Department of Mathematics, Islamic Azad University, Rasht Branch, Rasht, Iran.
Department of Mathematics, Islamic Azad University, Hadishahr Branch, Hadishahr, Iran.
Conventional data envelopment analysis (DEA) models normally assume all inputs and outputs are real valued and continuous. However in problems some inputs and outputs can only take integer values, also, both desirable and undesirable outputs can be generated . In this paper the effect of undesirable outputs in integer DEA model is discussed. The proposed model distinguishes weak disposability of outputs imposing non-uniform abatement factor.