Optimum Time-Censored Step-Stress PALTSP with Competing Causes of Failure Using Tampered Failure Rate Model

摘要

In this paper accelerated life testing is incorporated in life test sampling plans to induce early failures of high reliability items. Life test under accelerated environmental conditions may be fully accelerated or partially accelerated. In fully accelerated life testing all the test units are run at accelerated condition, while in partially accelerated life testing they are run at both normal and accelerated conditions. Many products have more than one cause of failure. Optimum time-censored step-stress partially accelerated life test sampling plan (PALTSP) with competing causes of failure has been designed using tampered failure rate model and variable repetitive group sampling plan. The optimum plan consists in finding out optimum stress change point and optimum sample size by minimizing the average sample number of a lot such that producer's and consumer's interests are safeguarded. Bilevel programming approach is used for the purpose. The method developed has been explained using an example.