Optimum degradation test plan under model mis-specification for Wiener and gamma processes

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


Degradation tests have been used for the purpose of assessing reliability information. In this paper, we consider a degradation test design problem under a statistical model mis-specification scenario. The Wiener and gamma processes are considered in this research. A gamma process is suitable for describing degradation paths that exhibit monotone behavior. However, if one fits a Wiener process model to the data, the resulting statistical inferences may be affected. Tsai, Tseng, and Balakrishnan studied the effect on the estimated mean time to failure. However, the experimental design problem was not discussed. A lack of the explicit functional form of the estimation variances makes it difficult to find degradation plans that can improve test efficiency. In this paper, functional forms of optimal degradation test plans are proposed under model mis-specification. Furthermore, a weighted ratio objective function considering the prior probability of the true model is used to find robust test plans for practical use. The results from a numerical example show that, by using an appropriate degradation test plan, the estimation variance can be reduced, and the test efficiency can be improved. A simulation study is conducted to investigate the performance of the parameter estimates when the sample size is small.

Original languageEnglish
Pages (from-to)1719-1732
Number of pages14
JournalCommunications in Statistics: Simulation and Computation
Issue number5
Publication statusPublished - 2023

All Science Journal Classification (ASJC) codes

  • Statistics and Probability
  • Modelling and Simulation


Dive into the research topics of 'Optimum degradation test plan under model mis-specification for Wiener and gamma processes'. Together they form a unique fingerprint.

Cite this