A unified network-DEA model for performance measurement of production systems

Traditional DEA methods treat a production unit as a black box without any consideration to the internal relations of its sub-processes. In recent DEA literature, there are many researches about production systems with network structure, in which outputs of some stages could be considered as the inputs of some other stages in producing final outputs. In most of these works, network systems assume to have special parallel or series structures. Although in real world applications, production processes are often complex and there is no complete and unified model available for performance evaluation of these general network systems. This paper introduces a unified general model for efficiency evaluation of network production systems when arbitrary relations between individual sub-processes are allowed. The new general network DEA model is then illustrated by some numerical examples.