Reliability Calculation of Product Failure Data (Part I : Theory)

The failure data of products are random and discrete, showing obvious uncertainty, which bring great inconvenience for reliability calculation. In this, the experience value of median rank, Weibull distribution, lognormal distribution and maximum entropy probability distribution are proposed to describe the distribution information of product failure data. The model of Weibull distribution includes two and three parameters Weibull distribution, and lognormal distribution includes two parameters and three parameters lognormal distribution. Each calculation model reflects different aspects of the information, whose merits shouldn't be blindly judged, but we can analyze a specific product or a group failure data is suitable for what kind of reliability model.