Fuzzy efficiency measures in data envelopment analysis

The existing data envelopment analysis (DEA) models for measuring the relat ive efficiencies of a set of decision making units (DMUs) using various inp uts to produce various outputs are limited to crisp data. To deal with impr ecise data, the notion of fuzziness has been introduced. This paper develop s a procedure to measure the efficiencies of DMUs with fuzzy observations. The basic idea is to transform a fuzzy DEA model to a family of conventiona l crisp DEA models by applying the a-cut approach. A pair of parametric pro grams is formulated to describe that family of crisp DEA models, via which the membership functions of the efficiency measures are derived. Since the efficiency measures are expressed by membership functions rather than by cr isp values, more information is provided for management. By extending to fu zzy environment, the DEA approach is made more powerful for applications. ( C) 2000 Elsevier Science B.V. All rights reserved.