It should be recognized, though, that service failures are just partial indicators of system reliability. Large-scale failures are too rare and too complex for direct statistical data to be meaningful. The ability of the system to avert or promptly recover from such failures and the means for doing so must be determined through analyses of the root causes of such events as they occur, augmented by predictive reliability models. Reliability at all levels is usually the cumulative result of decisions that were made over the span of many years, often for an assumed future that did not come to pass. Better planning decisions, whether they are in the area of capacity investments or coordination of protective relays, are the key to better reliability.
Technology can provide better tools for making decisions.
However, these tools cannot provide the answer to the question of how electric system reliability links to human health and safety or to the economy at large. POST Findings 5. Cable condition is not accurately assessed by conventional diagnostics and practices, which may accelerate cable failure. The harsh environment in which cables are located contributes to reliability problems. Load predictions have been inadequate.