Open Access
December 2013 How do heterogeneities in operating environments affect field failure predictions and test planning?
Zhi-Sheng Ye, Yili Hong, Yimeng Xie
Ann. Appl. Stat. 7(4): 2249-2271 (December 2013). DOI: 10.1214/13-AOAS666


The main objective of accelerated life tests (ALTs) is to predict fraction failings of products in the field. However, there are often discrepancies between the predicted fraction failing from the lab testing data and that from the field failure data, due to the yet unobserved heterogeneities in usage and operating conditions. Most previous research on ALT planning and data analysis ignores the discrepancies, resulting in inferior test plans and biased predictions. In this paper we model the heterogeneous environments together with their effects on the product failures as a frailty term to link the lab failure time distribution and field failure time distribution of a product. We show that in the presence of the heterogeneous operating conditions, the hazard rate function of the field failure time distribution exhibits a range of shapes. Statistical inference procedure for the frailty models is developed when both the ALT data and the field failure data are available. Based on the frailty models, optimal ALT plans aimed at predicting the field failure time distribution are obtained. The developed methods are demonstrated through a real life example.


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Zhi-Sheng Ye. Yili Hong. Yimeng Xie. "How do heterogeneities in operating environments affect field failure predictions and test planning?." Ann. Appl. Stat. 7 (4) 2249 - 2271, December 2013.


Published: December 2013
First available in Project Euclid: 23 December 2013

MathSciNet: MR3161721
zbMATH: 1283.62210
Digital Object Identifier: 10.1214/13-AOAS666

Keywords: Accelerated life test data , field failure data , frailty model , heterogeneous operating conditions , optimal plan

Rights: Copyright © 2013 Institute of Mathematical Statistics

Vol.7 • No. 4 • December 2013
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