Estimation method of maintenance replacement rate in MRO enterprise based on Weibull distribution

To satisfy uncertain requirements for spare parts, enterprise had to maintain a large number of spare parts inventory which led to aggravation of the cost pressure of the enterprise. To improve this situation, a statistical study on the maintenance replacement rate of the locomotive Maintenance, Repair and Overhaul (MRO) was conducted. Using components' replacement frequency to determine the rationality of replacement rate was discussed. The statistic analysis from the historical data of the locomotive MRO enterprise suggested that the components' replacement rate was conforming to Weilbull distribution of two parameters. The least square method was applied to estimate the parameters distribution. By calculating the errors of the fitting curve, the maximum error of the replacement rate distribution was 2.8414% and the average error was 1.1062%.