WAYNE B. NELSON, PhD, is a leading expert on analysis of reliability and accelerated test data. Formerly with General Electric Research & Development for twenty-three years, he now privately consults on and teaches engineering applications of statistics for many companies, professional societies, and universities. For his outstanding contributions to reliability data analysis and accelerated testing, he was elected a Fellow of the Institute of Electrical and Electronics Engineers, the American Society for Quality, and the American Statistical Association.