This dataset allows for the monthly computation of the System Average Interruption Duration Index (SAIDI) for the City of Mesa’s electric utility. The System Average Interruption Duration Index is commonly used as a reliability indicator by electric power utilities. It measures the average outage duration for each customer served and is calculated by taking the sum of the total customer minutes of service interruptions and dividing that by the total number of customers served. Data reporting may have a lag of 14 days.