Maintenance planning optimization based on PHM information and spare parts availability

Abstract

Maintenance planning plays an important role in assets management because it directly affects assets availability. In the aviation industry, maintenance planning becomes even more important due to the high availability expectations from aircraft operators and the high costs incurred when an aircraft becomes out of service. Gathering and combining all the relevant information to generate an optimized maintenance planning is not a simple task because the number of variables to be considered is high. The aim of this paper is to present a new model to plan maintenance interventions, using RUL (Remaining Useful Life) estimations obtained from a PHM (Prognostics and Health Monitoring) system. This information is used to verify whether spare parts will be available when the next failures are expected to occur. Since spare parts are finite resources, the goal of the proposed model is to reduce the probability that multiple similar components will fail in a short period of time because, when it happens, there is not enough time to repair all failed components and fleet availability is penalized. To avoid this situation, the model suggests the anticipation of some replacements. This paper presents a simulation comparing a situation in which PHM information is not available with the proposed model in terms of fleet availability and investment in spare parts. Life cycle cost considering a time horizon of 15 years was also computed in simulations. The results showed that the proposed model allowed an increase in fleet availability and a reduction in the lifecycle cost.