Data Envelopment Analysis in the Presence of Both Quantitative and Qualitative Factors

This paper presents a framework for incorporating ordinal data factors into the standard ratio DEA model. An application involving the prioritization of R&D projects is presented as a case in point where such ordinal factors appear in a natural way. Two different models for incorporating ordinal data are developed; one in which the ordinal factors are ranked and one where they are not. Finally, the issue of selecting a lower bound ɛ on factors is addressed.