Availability analysis of task system with the consideration of PHM

PHM (Prognostics and Health Management) is an engineering technology focusing on failure prognostics and so it has critical effects on the performance of the task system. In this paper, the qualitative analysis method of FMEA (Failure Mode and Effects Analysis) is proposed to analyze the prognostics' performance of PHM system and five corresponding evaluation parameters are derived. Based on some elementary assumptions, a simulation model with the consideration of characteristic parameters of PHM system is established. When coping with the simulation process, the effect of false alarm on the system's availability is also considered. Through massive cases, the influence of PHM system's performance on availability were discussed by univariate analysis and multi-factor coupling effect analysis. The results can be used to modify PHM system so as to improve the availability of the task system.