Optimal design of a simple step‐stress accelerated life test under progressive type I censoring with nonuniform durations for exponential lifetimes. (9th July 2019)

• Record Type: Journal Article
• Authors: Han, David
• Other Names: Stillman Eleanor guestEditor.; Triantafyllopoulos Kostas guestEditor.
• Is Part Of: Quality and reliability engineering international. Volume 35:Number 5(2019)
• Page Start: 1297
• Page End: 1312
• Publication Date: 2019-07-09
• Subjects: accelerated life tests -- design of experiment -- exponential distribution -- Fisher information -- progressive type I censoring -- step‐stress loading; Reliability (Engineering) -- Periodicals; Quality control -- Periodicals; High technology -- Periodicals; 620.00452
• DOI: 10.1002/qre.2523
• Languages: English
• ISSNs: 0748-8017

Abstract

Abstract: Thanks to continuously advancing technology and manufacturing processes, the products and devices are becoming highly reliable. However, performing the life tests of these products at normal operating conditions becomes extremely difficult, if not impossible, due to their long life spans. This can result in missed opportunities to introduce the products to the market in a timely manner and eventually loss of the market share. This problem is solved by accelerated life tests where the test units are subjected to higher stress levels than the normal usage level so that information on the lifetime parameters can be obtained more quickly. The lifetime at the design condition is then estimated through extrapolation using a regression model. In this work, the design optimization of a simple step‐stress accelerated life test under progressive type I censoring is studied with nonuniform step durations for assessing the reliability characteristics of a solar lighting device. Allowing the intermediate censoring to take place at the stress change time point, the nature of the optimal stress duration is demonstrated under various design criteria including D ‐optimality, C ‐optimality, A ‐optimality, and E ‐optimality. The existence of these optimal designs is investigated in detail for exponential lifetimes with a single stress variable, and the effect of the intermediate censoring proportion is assessed on the design efficiency.