Corrective maintenance timetable in restructured distribution environment

Outsourcing of maintenance activities from the core distribution operator business prompted the reorganization of the operations sequence of activities and affects, to some extent, the reliability of the distribution network. Repair times, a major component in the reliability calculations, arrive to a new understanding from operations point of view and the adequacy of established probabilistic representations has to be assessed. This paper proposes a mechanism to identify the layout of the sequence of activities for distribution component repair, resulting from reorganization, and revises the adequate representation of the times associated with various stages of the derived repair process. Statistical-based techniques employing estimates of distribution parameters and hypothesis testing serve to determine probabilistic distributions. The validity of the independence assumption for the random variables associated with individual times which compose the repair time is checked via statistical methods in order to confirm applicability of probabilistic-based calculations. By means of such a mechanism, an objective analysis of the time components of the repair time can be conducted, such as areas of improvement, and can be outlined. The results obtained for a large real power distribution system are presented.