Finding interrelationships and influential weights of selected key performance indicators: important considerations in developing an overall performance index for water supply systems

Performance indicators are rapidly becoming popular in performance assessment of water supply systems (WSSs) for finding the weaknesses and solving them. The selection and use of the key performance indicators (KPIs) for WSSs need the consideration of the regional and local conditions. Moreover, analyzing the results of the assessment requires a clear understanding of the relationship and intensity of the interaction of the KPIs with each other and the overall performance index. In this study, fuzzy Delphi method was used for selecting the KPIs in four dimensions for urban WSSs of Iran. Then, influential network relationship map of dimensions and selected indicators were determined and constructed by using fuzzy DEMATEL method. To facilitate the draw of the maps and more clarity, K-means clustering was used. Then, influential weights of the KPIs were calculated by using fuzzy DANP method. Among the KPIs, Aging of Mains related to the organizational dimension is the most independent and causal one. Further, Complaints related to the social dimension are the most dependent and affected indicator. The organizational dimension is the most causal dimension with high influence on the environmental, economic, and social dimensions. Therefore, the organizational dimension should be prioritized for improving the other dimensions and should be well-promoted to have a positive impact on overall performance. The outcomes provide a good guide for WSSs management, and researchers can use the data and methods of this study in other similar fields.