Efficiency evaluation of leakage management using data envelopment analysis

In this study, a cluster analysis was conducted to examine differences in leakage-management (LM) efficiency. The authors next conducted a data envelopment analysis to examine the efficiency of LM in water distribution systems on the basis of four input factors-active LM cost, rapid and accurate leakage-repair cost, appropriate pipe-body-management cost, and indirect labor cost for pipe network management. These factors represent the direct LM cost during a five-year period (2006-2010). The output factor was defined as the leakage reduction directly attributed to LM activities. The optimal efficiency point of each LM cost, calculated on the basis of the efficiency evaluation results, was used to conduct multiple regression analysis. The analysis results were examined to develop an economical LM model that could be used to predict the optimal combination of LM methods.