Maintainability evaluation of machining center with small samples

In recent years, some subsystems of machining center show the characteristics of long life, less faults and less maintenance. In these long-life subsystems, not only the maintenance data distributed in each subsystem is less, but also the prior information about the maintainability of the subsystem is less. In view of this situation, the lognormal distribution model is transformed into a normal distribution model, and a normal distribution small sample modeling method without prior information is used to establish the maintainability model of each subsystem. Then the maintainability of each subsystem is evaluated. The results show that the proposed method is obviously better than traditional large samples estimation method. The conclusion lays a foundation for the improvement measures of machining center credibility.