Abstract

There are two types of failures that occur on naval battleships. One is normal failure. This is not fatal as it can still carry out its mission if it does occur. On the other hand, critical failure is fatal because it must enter the home port immediately upon occurrence. Unlike normal failure, critical failure occurs with an extremely small probability and has the characteristics of a rare event. The critical failure data of battleships is too small to estimate the distribution. For this reason, in previous studies, only the constant expected value of critical failure was estimated. The variance of failure phenomena is usually very large. That is, a failure cannot be represented by a single constant expected value. Therefore, in this study, the variance of major failures by age of battleships was estimated over the entire lifespan of battleships. Investigate the relationship between critical failure and normal failure, and use this to estimate the population distribution of critical failure. The results of this study warn of the need to improve the Navy's maintenance capabilities. The novelty of this study is that it presented a method for estimating the population of rare events.