Reliability growth test planning of repairable systems using subsystem failure distribution data

Reliability growth testing has been widely used for assessing the reliability of complex systems in the automotive, aerospace, and oil and gas industry. The traditional common and practiced approach of RGT is to assess the initial reliability of the system by building and testing few prototypes for a period of time that extends from few months to years. Based on the initial reliability, initial testing time, and reliability target; the total testing time is determined using power law based models such as Dune and AMSAA/Craw models. Although this approach has been used for many years, it has been challenged by project managers (PM´s) since it hinders them from planning upfront the time and cost it takes to finish RGT and commercialization. A new alternative to traditional RGT planning using non-repairable component failure distribution data for system initial reliability assessment is proposed in this article. The proposed method will be demonstrated using real-life example of hydraulic system composed of several non-repairable subsystems with different failure distributions. The proposed method provides practitioners a mean to estimate total testing time required for RGT plans.