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A number of reliability indexes are used in the electric industry to make it easier to compare <br /> performance of electric utilities. Listed below are the reliability indexes along with ERMU's <br /> 2015 and 2016 statistics. Also attached is the American Public Power Association's (APPA) <br /> eReliability Annual Report which contains published averages that can be used by utilities to <br /> better understand the performance of their electric system relative to other utilities nationally and <br /> to those within their region or size class. <br /> Average Service Availability Index (ASAI) <br /> ASAI is a measure of the average availability of the sub-transmission and distribution systems to <br /> serve customers. It is the ratio of the total customer minutes that service was available to the total <br /> customer minutes available in a time period. This is normally expressed as a percentage. <br /> ERMU's 2016 ASAI is 99.9922%Availability ERMU's 2015 ASAI is 99.9943%Availability <br /> Customer Average Interruption Duration Index (CAIDI) <br /> CAIDI is defined as the average duration (in minutes) of an interruption experienced by customers <br /> during a specific time frame. It is calculated by summing the customer minutes off during each <br /> interruption in the time period and dividing this by the number of customers experiencing one or more <br /> sustained interruptions during the time period. The resulting unit is minutes. The index enables utilities to <br /> report the average duration of a customer outage for those customers affected. <br /> ERMU's 2016 CAIDI is 150.4193 minutes ERMU's 2015 CAIDI is 71.157 minutes <br /> System Average Interruption Duration Index (SAID!) <br /> SAID! is defined as the average interruption duration for customers served during a specified time <br /> period. It is determined by summing the customer minutes off for each interruption during a specified <br /> time period and dividing that sum by the average number of customers served during that period. The <br /> unit is minutes. This index enables the utility to report how many minutes' customers would have been <br /> out of service if all customers were out at one time. <br /> ERMU's 2016 SAIDI is 41.0234 minutes ERMU's 2015 SAIDI was 23.723 minutes <br /> System Average Interruption Frequency Index (SAIFI) <br /> SAIFI is defined as the average number of times that a customer is interrupted during a specified <br /> time period. It is determined by dividing the total number of customers interrupted in a time period by the <br /> average number of customers served. The resulting unit is "interruptions per customer." <br /> ERMU's 2016 SAIFI is 0.2727 ERMU's 2015 SAIFI was 0.333 <br /> El <br /> POWERED DI <br /> Page 2 of 3 <br /> NATURE <br /> Reliable Public <br /> Power Provider POWERED To S ERV E <br /> 92 <br />