Change‐point detection in failure intensity: A case study with repairable artillery systems

Repairable systems can experience unexpected environmental changes over long operational periods. Such changes affect the incidence of failures, causing different system failure patterns before and after the changes. In this article, we propose an informational change‐point approach for the pattern of recurrent failures in repairable artillery systems. Unlike other trend tests, this approach provides additional information about the locations of change‐points over rates of occurrence of failures (ROCOFs) as well as failure trends. We adopt the modified information criterion (MIC) proposed by Pan and Chen (2006) to detect the locations of the changes and propose sequential procedures for determining the number of change‐points in independent exponential sequences. The change‐point approach is applied to unscheduled maintenance data from eight artillery system exercises performed by the Republic of Korea Army. The change‐point test along with a graphical presentation of estimated ROCOF lines can provide easy interpretation of changes in failure trends/intensities in a homogeneous Poisson process.