Developing the Overall Performance Index for Water Supply Systems based on Fair Benchmarking and Strong Sustainability

Abstract

Performance assessment indicators play a crucial role in evaluating water supply systems (WSSs). Developing a Composite Indicator (CI) that integrates key performance indicators (KPIs) offers significant advantages. This study aims to explore various aspects of creating a CI for assessing WSS performance, including clustering, normalizing, weighting, and aggregating KPIs. Data corresponding to selected KPIs from diverse WSSs in Iran were collected and categorized into four dimensions: Environmental, Financial, Organizational, and Social, to ensure comprehensive performance evaluation and calculation of an Overall Performance Index (OPI). A new multi-criteria method was employed to assign weights to KPIs in the CI Based on the concept of non-compensation. WSSs were grouped into clusters based on population, water resource type, and climate, and KPIs were normalized accordingly based on fair benchmarking. A non-linear (Geometric) method was utilized to aggregate KPIs, emphasizing strong sustainability and non-compensation interactions. The change in the results of the selected method was compared with the previous methods. The study found that method variation at each stage of CI development significantly affected the OPI and ranking of WSSs. Population emerged as a significant factor, and key findings include the substantial impact of resource type and climate on specific KPIs, underscoring the need to consider influencing factors in benchmarking. The non-linear aggregation method demonstrated greater rigor and sustainability compared to linear methods, aligning with principles of fair benchmarking and WSS sustainability.