Planning step-stress life-test with a target acceleration-factor

• Published in: IEEE transactions on reliability Vol. 48; no. 1; pp. 61 - 67
• Main Authors: YEO, K.-P, TANG, L.-C
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-03-1999; Institute of Electrical and Electronics Engineers
• Subjects: Acceleration; Applied sciences; Data analysis; Exact sciences and technology; Extrapolation; Life estimation; Life testing; Maximum likelihood estimation; Operational research and scientific management; Operational research. Management science; Reliability theory. Replacement problems; Sequential analysis; Stress; Time factors; Accelerated aging test; Exponential distribution; Multistep method; Reliability; Sequential method; Optimal design
• ISSN: 0018-9529; 1558-1721
• DOI: 10.1109/24.765928

A sequential approach is presented to plan a multiple-steps step-stress accelerated life test (SSALT) with type-I censoring so as to achieve a pre-specified acceleration factor. An initial optimal plan for a simple SSALT, where one not only has to determine the optimum hold-time under low stress but also the optimum low stress level, is obtained by solving a constrained nonlinear program. A backward recursion scheme generates the subsequent optimal low-stress levels and hold-times for multiple-step SSALT. An illustration using a 3-step SSALT is presented. The relative efficiency of the 2-step and 3-step SSALT is investigated. A numerical example illustrates the method under 2-step and 3-step SSALT.