A Censored Sequential Posterior Odd Test (SPOT) Method for Verification of the Mean Time To Repair

The verification of the Mean Time To Repair (MTTR) is a problem of interest in many practical cases. As maintenance time can often be adequately described by a lognormal distribution, the problem leads us to research on statistical inference on the mean of the lognormal distribution. To achieve this purpose, we propose the Sequential Posterior Odd Test (SPOT) method for verification of the unknown parameter of the lognormal distribution. We first present a model to determine a threshold in the SPOT method for verification of MTTR. Moreover, the Censored SPOT method is proposed when the sample size (usually small) is fixed. A numeric example with comparison is discussed to illustrate advantages of the Censored SPOT method.