Vulnerability assessment in the water supply system is a systematic process of identifying weaknesses that may affect the availability, quality, reliability, and sustainability of water services. In the context of smart cities, vulnerability assessment is essential for ensuring safe drinking water, protecting public health, improving resilience against disasters, and supporting sustainable urban development. It helps planners and utility managers recognize risks and implement preventive measures before failures occur. One of the primary elements of vulnerability assessment is source vulnerability. Water sources such as rivers, lakes, reservoirs, and groundwater aquifers must be evaluated for susceptibility to pollution, depletion, seasonal variability, and climate change. Industrial discharges, agricultural runoff, excessive groundwater extraction, and encroachment can threaten the quality and quantity of water sources. Smart monitoring systems can continuously assess these risks through sensors and remote sensing technologies. Another important element is water quality vulnerability. Assessment involves identifying possible contamination from biological, chemical, and physical pollutants. Water quality monitoring should evaluate pathogens, heavy metals, pesticides, turbidity, and other contaminants. Smart cities use real-time water quality sensors and automated warning systems to detect contamination and respond quickly, minimizing health risks to consumers. Infrastructure vulnerability is another critical component. Pipelines, pumping