Optimizing product reliability? This research explores alternative methods for planning constant-stress and step-stress accelerated life tests (ALT), crucial for ensuring product longevity and performance. In constant-stress ALT, the study considers test plans that optimize not only the stress levels but also the sample allocation, reducing inconsistencies when data are plotted. For step-stress ALT, the research optimizes both stress levels and holding times to achieve a target acceleration factor that meets test time constraints with a desirable failure fraction. The findings suggest that increasing lower stress levels and decreasing initial sample allocations in constant-stress ALT enhances the acceleration factor. Similarly, reducing initial hold times in step-stress ALT achieves the same effect. Formulated as constrained nonlinear programs, these methods provide statistically optimal ways to plan accelerated life tests, benefiting reliability engineering and product development.
Published in the International Journal of Reliability, Quality and Safety Engineering, this paper directly addresses the journal’s core topics. By presenting innovative test plans for accelerated life tests, the research contributes to methodologies that enhance product reliability and safety, aligning with the journal’s focus on engineering applications.