Optimal design of variables switch-based sampling scheme for verifying Weibull distributed product lifetimes

J Appl Stat. 2024 May 30;52(1):119-134. doi: 10.1080/02664763.2024.2360589. eCollection 2025.

Abstract

Ensuring products maintain their normal function during the warranty period is essential for companies to control warranty costs and sustain their brand reputation. A variables acceptance sampling (VAS) plan based on the lifetime performance index (LPI) is a practical technology for verifying product lifetimes because it can provide the number of failures required for life testing and the acceptance criterion for lot disposition. Recently, an LPI-based variables quick-switch sampling (VQSS) system has been developed to improve the sampling efficiency. The VQSS system manipulates the normal and tightened VAS plans for a series of lot dispositions. However, the existing LPI-based VQSS system only alters acceptance criteria to build normal and tightened VAS plans, which may limit its applicability. In this paper, we propose an LPI-based VQSS system with a mechanism that can alter the required number of failures. Compared to the existing LPI-based VQSS system, the proposed method has superior discriminatory power and moderate cost-effectiveness. Finally, we illustrate a lifetime verification of an electric vehicle's battery as a case study to demonstrate the practicality of the proposed method.

Keywords: Product lifetime; lifetime performance index; variables acceptance sampling plan; variables quick-switch sampling system; warranty.

Grants and funding

This work was partially supported by the National Science and Technology Council of Taiwan under grant number NSTC 112-2221-E-013-002-MY3.