Abstract
Data Envelopment Analysis models have evolved over the years, offering formulations that correspond to instances beyond strictly measuring performance. In this chapter, extensions of DEA models will be presented, demonstrating recent developments in DEA formulations. The models that will be analytically described and modelled with GAMS in this chapter concern DEA models with exogenously fixed variables and categorical variables, DEA models for handling desirable and undesirable outputs, congestion, and chance constraints.