Field Product Reliability Risk Assessment

Abstract

Probabilistic risk assessment is a systematic methodology to evaluate the likelihood of a risk associated with a concerned failure. It has been used in many industries such as nuclear, offshore oil and gas, environment protection, etc. For companies that design, manufacture, and sell products to customers like consumer electronic or automotive companies, it is about to evaluate the customer and warranty impact of a concerned failure of the product. Reliability validation tests are performed in product development and validation phase. Continuing reliability tests are ongoing in production phase. Failures are typically found in the tests. The tests are usually designed and executed as accelerated life tests. It is imperative to evaluate the discovered failure modes and make good decisions based on the risk assessment result. Life test data analysis (aka Weibull analysis) is the method to use for the analysis of product reliability and failure rate under the accelerated test stress condition. To relate it to the product reliability performance experienced by customers in the field, an acceleration model or acceleration factor is needed. Meanwhile, the field condition is generally complicated. The stress can be distributional, meaning individual customer uses their products with different stress level under different environmental condition. The product exhibits different reliability or failure rates under the different stress levels in the field.