A Partial Safety Factor Method for System Reliability Prediction With Outsourced Components

Abstract

System reliability is usually predicted with the assumption that all component states are independent. This assumption is particularly useful for systems with outsourced components. The assumption, however, may produce large errors in the system reliability prediction since many component states are strongly dependent. The purpose of this study is to develop an accurate system reliability method that can produce complete joint probability density function (PDF) of all the component states, thereby leading to accurate system reliability predictions. The proposed method works for systems whose failures are caused by excessive loading. In addition to the component reliability, system designers also ask for partial safety factors for shared loadings from component suppliers. The information is then sufficient for building a system-level joint PDF. Algorithms are designed for a component supplier to generate partial safety factors, which enables accurate system reliability predictions without requiring proprietary information from component suppliers.