An input-and output-oriented data envelopment analysis model

Considering the conventional data envelopment analysis （DEA） model used to measure the relative efficiencies of a group of decision making units （DMUs） is limited to either input or output orientation, a new DEA model which is both input-and output-oriented is proposed in this paper. This model can be treated as a multi-objective programming problem and solved by fuzzy sets theory. The basic idea is to describe the efficient frontier with fuzzy observation and determine projections for DMUs on the frontier by using the fuzzy optimization approach. The measurement of efficiencies for DMUs is obtained by comparing the inputs and outputs of DMUs with their projections. Since the input- and output-oriented DEA model can be transformed into a conventional input- or output-oriented DEA model by using special membership functions, it is therefore more adaptive for efficiency measurement. Finally, a typical example is presented to illustrate the computation methods.

An input-and output-oriented data envelopment analysis model