R. Kazemi Matin - Islamic Azad UniversityKaraj Branch - Department of Mathematics
A. Emirouznejad - Aston University-Aston Business School

Conventional Data Envelopment Analysis (DEA) models assume non-negative inputs and outputs. In many real applications, some inputs and/or outputs can take negative values. Recently, Emrouznejad et al. (2010) introduced a Semi-Oriented Radial Measure (SORM) for modeling DEA with negative data. This paper investigates the SORM model from both axiomatic foundation and efficiency measurement modeling and introduces a revised version of SORM.

DEA, Efficiency measurement, Negative data, Disposability