Two-Stage C2GS2 DEA Method for Ranking Based on the Optimal Frontier Surface

Evaluation and Ranking decision making units with independent subsystems is one of the hot problems in the area of data envelopment analysis(DEA) research. Applying the virtual optimal frontier surface concept , this paper puts forward the output and input nonradial two -stage C²GS² data envelopment analysis model for evaluating and ranking the decision making units with independent subsystems based on the nonequal proportion expansion or reduction thoughts. The method in this paper which has fewer calculation is objective and optimal, so it is a operable and practical DEA ranking method.