This paper sketches out a few of the more important concerns that electricity suppliers should account for when planning substation upgrades. The focus is on how best to increase the reliability, availability, and maintainability of power substation automation networks within the context of the IEC 61850 vision, to give electricity suppliers a clear idea of the design procedures, device tolerances, and hardware and software features they should expect from the engineers and manufacturers who design and build their networking and computing devices.