Classification of Data Envelopment Analysis models

This article contains a method for classifying Data Envelopment Analysis models. Two main criteria i.e. orientation and returns to scale are used. These criteria enable distinguishing between oriented and non-oriented DEA models with constant and variable returns to scale. Basic properties of input oriented and output oriented DEA models with constant returns to scale are illustrated using an example of the CCR model. The BCC model is used to characterize the oriented DEA model with variable returns to scale. A graphical presentation of the efficiency frontier and the efficiency measure and primal and dual programming problems are presented for both types of models. In the article an additive model is considered as an example of a non-oriented DEA model. Moreover, other ways of classifying DEA models are also shown.