Shanshan Lv

• Hebei University of Technology

In reliability improvement experiments, engineers are very interested in which factors affect the reliability of products. Furthermore, they hope to terminate experiment early without affecting the identified results. In this article, we assume the shape and scale parameters of Weibull distributions vary with experimental factors, and construct a B...

To achieve better product quality, the dual‐response surface has been widely used to simultaneously achieve targets for the mean and reduced variance. The general assumption is that the experimental data are normally distributed without censoring. However, reliability data are usually non‐normally distributed and censored. Consequently, the classic...

Return of products within the warranty coverage induces additional cost and loss of reputation to manufacturers. It is of practical interest to predict the return rate by experimental means before introducing a product to the market. In this paper, we propose to optimize accelerated reliability tests to achieve the goal within limited time. To desc...

Many process parameters may affect product reliability significantly. Manufacturers need to identify the key processes and optimize their parameter levels. Traditional methods only improve product lifetime through maximizing the location parameter. They ignore the robustness of the product. In this article, we improve product lifetime and reduce va...

Product quality and reliability characteristics are important considerations for all manufacturers in the product and process design. Industrial experiments may include both quality and reliability characteristics with the goal to obtain a compromise optimization of the two responses. In many cases, such experiments do not use a completely randomiz...

Manufacturing process parameters often affect product reliability significantly. Practitioners need to improve product lifetime and reduce its variance simultaneously by optimizing process parameters. However, an important feature of lifetime distributions is that the variance increases as the mean increases. Practitioners should make a trade-off b...

In practice, engineers seek to find reasonable solutions for complex and unstructured problems, which are common in many areas. The workable solutions for these problems are never a one-shot experiment and data analysis procedure. Rather, the proper solution for these problems requires an inductive-deductive process which involves a series of exper...

Many reliability experiments are not completely randomized. Instead they involve subsamples, blocks, split-plot structures, etc. A common analysis often uses random effects to account for the impact of the experimental protocol. The two-stage method is an easy way for practitioners to incorporate random effects in the analysis. This article compare...

Accelerated life tests usually contain subsampling, which represents a restriction on randomization. The two-stage approach can deal with lifetime data from experiments with subsampling. However, this method did not introduce how to reduce the biases of estimators and compute confidence intervals of low percentiles. In this article, we build the mo...

Lower percentiles of product lifetime are useful for engineers to understand product failure, and avoiding costly product failure claims. This paper proposes a percentile re-parameterization model to help reliability engineers obtain a better lower percentile estimation of accelerated life tests under Weibull distribution. A log transformation is m...

Many practical situations have both a quality characteristic and a reliability characteristic with the goal to find an appropriate compromise for the optimum conditions. Standard analyses of quality and reliability characteristics in designed experiments usually assume a completely randomized design. However, many experiments involve restrictions o...

We discuss here the estimation of lower percentiles by assuming a Weibull distribution. A log-transformation is made with the Weibull distribution to a smallest extreme value distribution. The location parameter of SEV is re-parameterized by a particular 100pth percentile and the scale parameter of the transformed distribution is assumed to be nonc...

In accelerated life tests (ALTs), test units may come from different groups (subsampling, blocking, and clustering) and the group effect is random and significant. The ALTs, in this case, are not completely randomized designs (CRDs). Previous studies on ALTs assume that the failure mechanism of Weibull distribution remains constant over all acceler...

Due to cost and time limitation, reliability experiments usually contain subsampling which is a restriction on randomization. Two-stage approach can analyze right censored Weibull distributed reliability data with subsampling. However, the confidence intervals of low percentiles cannot be obtained by two-stage approach. Moreover, the shape paramete...