Chi-Squared Accelerated Reliability Growth model

A Chi-Squared Accelerated Reliability Growth (CARG) model has been developed as a new method for single- and multi-stress level reliability growth life data analysis. The model is relatively easy to apply and is very practical. The CARG method is appropriate when an exponential distribution can be assumed. The chi-squared distribution has been used as a traditional method of identifying reliability confidence bounds for the exponential failure lifetime behavior of components, assemblies, and systems and is often extended to accelerated life test data analysis. The distribution is key for assessment when observance of few or even zero failures occur in accelerated testing for estimates on reliability at a statistical significance level. It is therefore natural to consider using the chi-squared method in the application of accelerated reliability growth data analysis. Using the statistic, the model is demonstrated on a manufacturing data set consisting of single accelerated stress and multi-accelerated stress tests. Reliability growth predictions show good agreement with the product´s field data.