Multistate Reliability Model and Quality Loss Analysis

9500126杨，本研究将动态多状态可靠性模型与质量损失分析相结合，以描述作为时间函数的产品性能退化。在该建模方法中，产品性能水平被表示为任意给定时刻产品设计参数和环境因素的函数。将定义衡量产品在一段时间内的性能水平的质量损失函数。通过建立模型和损失函数，实现了可靠性驱动的产品参数设计、产品性能评价、可靠性驱动的产品容差设计以及可靠性和健壮性设计的集成。这项研究部分建立在与福特汽车公司合作研究基于可靠性的汽车系统蒸发排放的基础上，将蒸发排放作为典型的性能退化问题。与福特汽车公司的合作使这项研究的结果得以验证，方法是将理论研究与基于可靠性的实际研究相结合，对1995年及以后的车型年机动车燃油系统的蒸发排放进行研究。这项研究将有助于机动车制造商满足《清洁空气法》规定的、由美国环保局和加州空气资源委员会制定的新的蒸发排放标准。它还将开发可靠性驱动的产品设计技术，并建议可更普遍使用的稳健设计集成策略。

9500126 Yang This research integrates dynamic multistate reliability model and quality loss analysis in order to describe the product performance degradation as a function of time. In this modeling approach the product performance level is expressed as the function of product design parameters and environmental factors at any given time. A quality loss function which measures the product performance level over a time period will be defined. The model and loss function then lead to reliability-driven product parameter design, product performance evaluation, reliability-driven product tolerance design, and reliability and robust design integration. The research is partially built upon work in collaboration with the Ford Motor Company on reliability-base motor vehicle system evaporative emission, using evaporative emission as a typical performance degradation problem. Collaboration with Ford Motor Company allows the results of this research to be validated by combining the theoretical research with a practical reliability-based study of a motor vehicle fuel system's evaporative emission for 1995 and subsequent model years. This research will contribute to motor vehicle manufacturers' ability to meet new standards for evaporative emission governed by the Clean Air Act and set by the EPA and the California Air Resource Board. It will also develop techniques for reliability-driven product design and suggest robust design integration strategies that can be used more generally.