Introducing multi-agent (MA) technology into a SCADA (Supervisory Control and Data Acquisition) system can improve the serviceability and enhance maintenance-free operation with the inter-terminal parameter (ITP) method. In addition, the system's distributed intelligent field terminals (IFTs) use a common algorithm that is unaffected by any changes to the system specifications. As a result of these innovations, the proposed system has much better serviceability because it is much easier to make modifications compared to that of conventional systems. This system has been implemented for practical purposes at over 60 sites.