Robustness of age replacement strategy in maintenance management

The robust problem of age replacement models in maintenance management is discussed in this paper. The characters of optimal solutions of age replacement models, with cost and availability objects, are presented. A new algorithm based on Newton method is established to calculate the optimal maintenance interval and cost rate. Comparing with the TTT (Total Time on Test) plot method, much faster calculation and better accuracy were achieved. Some values of a parameter are fixed to investigate the variation of optimal maintenance interval and costs when changing the values of the other parameters. The Weibull distribution is used as the typical distribution of products life time, and 3D and 2D plots are used to show the parameter sensitivity. By the sensitivity analysis, it is found that the age replacement strategy is usually robust when all the parameters values are great enough.