| Article ID: | iaor2005783 |
| Country: | China |
| Volume: | 23 |
| Issue: | 4 |
| Start Page Number: | 11 |
| End Page Number: | 16 |
| Publication Date: | Apr 2003 |
| Journal: | Systems Engineering Theory & Practice |
| Authors: | Ma Zhanxin |
| Keywords: | sets |
In this paper, a characterization of effective units is given, and a necessary and sufficient condition for DEA efficiency is provided. At the same time, something about the significance and theoretic basis of DEA efficiency is discussed using the theory of partially ordered sets. A method for using qualitative variables in Data Envelopment Analysis is given.