Efficiency assesment using non radial projection in DEA models

Data envelopment analysis (DEA) is used as a tool for technical efficiency evaluation of decision making units. These units are compared with each other. The comparison is based on the size of inputs and outputs. In case of an inefficient unit, there is a possible of ordaining necessary changes for achievement of the efficiency frontier. There is a problem when the recommendations for inefficient units given by the classical DEA methods are unrealistic. Modified DEA models (Weighted Slack-based measure of efficiency model; Generic directional distance model) have been developed to eliminate this problem.