Abstract:

Product reliability is a function of effective usage and applied stress (both operational and environmental) conditions. In real life, both usage and stress levels are not fixed, but random variables; i.e., they are statistically distributed. During engineering life test design, people often pick the high percentiles for population usage and stress level as the field reference for the sake of conservativeness and safety margin, such as 90th percentile, 95th percentile, or even 99th percentile. This often yields very ambitious and even unrealistic test sample size and/or test duration requirements because the majority (say 90% or higher) of users in the field are assumed to be operating under extreme usage and stress conditions. The question often comes up as to which usage and stress percentile is the appropriate choice so that the overall population reliability is assured. Is it mean, median, or some other percentile (such as 60%, 70%, etc.)? This talk is trying to answer that question by introducing the so-called Reliability Equivalence Principle, and then presenting the analytical expression of reliability-equivalent reference usage and stress value so that the same reliability target can be achieved at the population level. Numerical example is given to illustrate the advantage of the method for reliability life test design over the traditional practice, especially for a high-reliability product.

Speaker’s Bio:

Dr. Frank (Feng-Bin) Sun is currently a Technical Lead and Principal Reliability Engineer at Tesla Inc. with over 30 years of industry and academia experience. He has published two books and more than 50 papers in various areas of reliability, maintainability and quality engineering. Dr. Sun served in the editorial board as an Associate Editor for the IEEE Transactions on Reliability from 1999 to 2003 and from 2016 to 2023, Program Chair of ISSAT International Conference on Reliability and Quality in Design since 2014, and a committee member and session moderator of numerous international conferences on reliability. He received his Ph.D. in Reliability from University of Arizona and is a senior member of ASQ and the President of Society of Reliability Engineers Silicon (SRE) Valley Chapter. Dr. Sun received the RAMS 2013 A.O. Plait Best Tutorial Award, RAMS 2020 P.K. McElroy Best Paper Award, and RAMS 2024 Doug Ogden Best Paper Award by an SRE Member.