Proportional hazards analysis of field warranty data

This paper describes a proportional hazards reliability analysis and some of the methods of statistical inference, based on asymptotic theory. The authors report application of the Weibull proportional hazards model to the analysis of actual field warranty data for automotive air conditioning compressors. Statistical inference is illustrated through asymptotic normal confidence intervals and the likelihood ratio test statistic. The research employed a commercial data set to test theories relevant to defensive systems reliability analysis, and illustrates technology transfer from defense-research to commercial applications.