Data Envelopment Analysis (DEA) is a methodology for analyzing production processes and for measuring productive efficiency. It originated from the seminal work by Charnes, Cooper and Rhodes (1978), Banker, Charnes and Cooper (1984) and Charnes, Cooper, Seiford and Stutz (1985). In the relatively short span of two decades, DEA has established itself as an important analytical tool. An increasing number of applications are evidence of its popularity among researchers and practitioners in the business community and in government institutions. However, the methodology suffered initially from a number of limitations [...]