Estimation procedures and optimal censoring schemes for an improved adaptive progressively type-II censored Weibull distribution

Abstract

This paper presents an effort to investigate the estimations of the Weibull distribution using an improved adaptive Type-II progressive censoring scheme. This scheme effectively guarantees that the experimental time will not exceed a pre-fixed time. The point and interval estimations using two classical estimation methods, namely maximum likelihood and maximum product of spacing, are considered to estimate the unknown parameters as well as the reliability and hazard rate functions. The approximate confidence intervals of these quantities are obtained based on the asymptotic normality of the maximum likelihood and maximum product of spacing methods. The Bayesian estimations are also considered using MCMC techniques based on the two classical approaches. An extensive simulation study is implemented to compare the performance of the different methods. Further, we propose the use of various optimality criteria to find the optimal sampling scheme. Finally, one real data set is applied to show how the proposed estimators and the optimality criteria work in real-life scenarios. The numerical outcomes demonstrated that the Bayesian estimates using the likelihood and product of spacing functions performed better than the classical estimates.

Keywords:

• Bayesian and frequentist estimators
• improved adaptive progressive censoring
• interval estimation
• optimum sampling plan
• Weibull distribution

Acknowledgments

The authors would like to thank the Editor-in-Chief, Associate Editor and the Reviewers for their constructive suggestions which helped us to improve the earlier version of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).