Dynamic network data envelopment analysis based upon technology changes

The existing dynamic models assume the technology is unchanged in which the same factor should have the same multiplier, no matter which process it is associated with. The internal network structures embedded in a multi-period system are ignored in the literature. The current paper considers that the technology is changed in the dynamic system The same factor may have different multipliers in different periods, except for the variables of intermediate measures connecting two stages in one period and flows connecting two consecutive periods. An additive aggregation dynamic network data envelopment analysis is developed to measure the multi-period systems with a two-stage process embedded in each period. The system efficiency, overall efficiency and stage efficiencies of each period can be derived, and the relationship between the system efficiency and period efficiencies can be identified. The newly developed dynamic network model is nonlinear, and can be transformed to a semi-definite programming problem. A case of high-tech industry in China is illustrated to the approach.