Congestion is a wasteful stage of the production process where outputs are reduced due to excessive amount of inputs. There are several approaches in data envelopment analysis (DEA) literatures to treat congestion. The concept of strong and weak congestion first developed by Tone and Sahoo [Tone, K., Sahoo, B.K., 2004. Degree of scale economies and congestion: A unified DEA approach. European J...

Data envelopment analysis (DEA) is a method for measuring the efficiency of peer decision making units (DMUs) which uses a set of inputs to produce a set of outputs. In some cases, DMUs have a two-stage structure, in which the first stage utilizes inputs to produce outputs used as the inputs of the second stage to produce final outputs. One important issue in two-stage DEA is the sensitivity of...