Optimal design of simple step-stress accelerated life tests for one-shot devices under exponential distributions

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

This paper considers simple step-stress accelerated life tests (SSALTs) for one-shot devices. The one-shot device is an item that cannot be used again after the test, for instance, munitions, rockets, and automobile air-bags. Either left-or right-censored data are collected instead of actual lifetimes of the devices under test. An expectation-maximization algorithm is developed here to find the maximum likelihood estimates of the model parameters based on one-shot device testing data collected from simple SSALTs. Furthermore, the asymptotic variance of the mean lifetime under normal operating conditions is determined under the expectation-maximization framework. On the other hand, the optimal design that minimizes the asymptotic variance of the estimate of the mean lifetime under normal operating conditions in terms of three decision variables, including stress levels, inspection times, and sample allocation is discussed. A procedure then is presented to determine the decision variables when a range of stress levels and the termination time of the test as well as normal operating conditions of the devices are given. The properties of the optimal design and the effects of errors in pre-specified planning values of the model parameters are also investigated. Comprehensive simulation studies show that the procedure is quite reliable for the design of simple SSALTs. Copyright © 2018 Cambridge University Press.
Original languageEnglish
Pages (from-to)121-135
JournalProbability in the Engineering and Informational Sciences
Volume33
Issue number1
Early online dateFeb 2018
DOIs
Publication statusPublished - Jan 2019

Fingerprint

Accelerated Life Test
Exponential distribution
Lifetime
Asymptotic Variance
Automobile air bags
Right-censored Data
Expectation Maximization
Expectation-maximization Algorithm
Automobile
Rockets
Maximum Likelihood Estimate
Termination
Maximum likelihood
Inspection
Planning
Optimal design
Life stress
Simulation Study
Minimise
Testing

Citation

Ling, M. H. (2019). Optimal design of simple step-stress accelerated life tests for one-shot devices under exponential distributions. Probability in the Engineering and Informational Sciences, 33(1), 121-135. doi: 10.1017/S0269964818000049

Keywords

  • Cumulative exposure model
  • EM algorithm
  • Exponential distribution
  • One-shot devices
  • Optimal design
  • Step-stress accelerated life-tests