Partially Accelerated Life Tests for the Weibull Distribution Under Multiply Censored Data

Abstract

This article aims to estimate the parameters of the Weibull distribution in step-stress partially accelerated life tests under multiply censored data. The step partially acceleration life test is that all test units are first run simultaneously under normal conditions for a pre-specified time, and the surviving units are then run under accelerated conditions until a predetermined censoring time. The maximum likelihood estimates are used to obtaining the parameters of the Weibull distribution and the acceleration factor under multiply censored data. Additionally, the confidence intervals for the estimators are obtained. Simulation results show that the maximum likelihood estimates perform well in most cases in terms of the mean bias, errors in the root mean square and the coverage rate. An example is used to illustrate the performance of the proposed approach.

Keywords:

• Acceleration factor
• Maximum likelihood estimation
• Partially accelerated life test
• Weibull distribution

Mathematics Subject Classification:

• 62N01
• 62N02

Acknowledgments

The authors gratefully acknowledge the referees of this article who helped clarify and improve this presentation. Also, the authors are grateful for financial support from the National Science Council in Taiwan under the grant NSC-98-2213-E011-068-MY3.