Setting reliability goals and assessing reliability improvement program effectiveness

Abstract

Establishing reliability goals is a crucial aspect of achieving and maintaining acceptable reliability performance. Ultimately, the level to which a utility's reliability must aspire is expressed as a set of goals reflecting the needs of a utility's stakeholders. Some of these stakeholders include residential/commercial/industrial customers, regulators and investors. Ameren Missouri integrates stakeholders' requirements into the reliability goal-setting process to establish an overall company goal for performance. This company goal then becomes the basis for establishing local performance goals at each of Ameren Missouri's geographic subsidiaries, or divisions. Inputs such as the number of previous customer interruptions, load density category and the number of overhead/underground circuit miles are used to equably allocate the company's overall goal to each division. Reliability improvement activities are then undertaken by division personnel to achieve these goals. After establishing reliability performance goals and implementing reliability improvement activities to meet these goals, a logical question to be answered is “How much reliability improvement was achieved by the completed program activities?” There are many different ways to assess the effectiveness of reliability improvement programs. For example, baseline performance prior to implementation of an improvement program is often compared to performance after program activities have taken place. While this approach is conceptually simple, random changes in the data make it impossible to prove that changes are the result of improvement activities. More sophisticated methods utilizing statistical process control charts or design of experiment techniques can be used by analysts to reliably assess the impact of reliability improvement programs. Ameren Missouri's use of these methods will be described and illustrated with practical examples as they relate to Section 3 of the P1782 Trial Use Guide.