Optimal Design for Accelerated Degradation Tests for Wiener Degradation Processes with Time-Censoring

• Activity Number: 539
• Type: Contributed
• Date/Time: Wednesday, August 4, 2010 : 10:30 AM to 12:20 PM
• Sponsor: Section on Quality and Productivity
• Author(s): Ming-Yung Lee*+ and Jen Tang
• Companies: Providence University and Purdue University
• Keywords: Wiener process ; Time-censoring ; degradation test ; optimal design

Abstract

In this paper, we study the optimal design of a general degradation test plan without pre-specifying the form of the stress function. We assume that, under a general time-varying stress function, the degradation of a product's performance is modeled by a time-transformed Wiener process. The objective function to be minimized to obtain the optimal test plan is the asymptotic variance of the sample pth quantile for the lifetime distribution at use conditions. Time-censoring is allowed, and a budgetary constraint is assumed. For the optimization problem just described and its "dual" problem, we prove the existence of an optimal or near-optimal step-stress plan and then provide a procedure for finding this step-stress plan. We use an example of Light Emitting Diode (LED) testing as a basis for an example of how to design an accelerated step-stress degradation test.