Development of a Multi-period Output Model for Considering Time Lag Effect

Abstract

Existing data envelopment analysis (DEA) models have focused on evaluating the relative efficiency of decision making units (DMUs) based on multiple input and output factors for the same period. However, a certain kind of lead time is sometimes required to produce outputs using inputs in an organization. R&D evaluation is a typical area with this kind of time lag. Thus, the purpose of this paper is to develop a new DEA model to deal with time lag effect in performance evaluation. The suggested model defines the efficiency measure of a DMU by using outputs of multiple periods in different view with existing multi-period input (MpI) model. Three varieties of the suggested model are presented by adding three kinds of constraints based on the different types of time lag effect. A case example using a real data set is given to demonstrate the usage or implications of the suggested models. In the experimental section, the results of the suggested models are compared with the results of CCR and the MpI model using the data set of the 21st Century Frontier R&D program which is a long-term national R&D program of Korea.