DOI: 10.36347/sjpms

Pages: 233-248

The customary two-stage data envelopment analysis model, measures overall performance of a system which includes two stages in a specific period of time. In these models, some variables (the variables between two stages) are ignored. This research develops the two-stage data envelopment analysis model in several time periods which makes possible the periodical and overall performance calculation in each stage as the weighted mean of the previous stage. Therefore, the performance of a two-stage system in one period is decomposed to performance of each period. This analysis is originated from identification of a unit under inefficient assessment. Concerning the model, in order to calculate the performance, also the common local weight of productivity index between two periods can be utilized and its performance is obtained by multiplying two sub-stages and the advances and retreats of a system can be discussed along two or several time periods. Considering the assumption of inaccurate data (interval data), cause the existing problem condition to be solved optimistically and pessimistically and the performance is achieved for the system