【作者】 吴静；

【导师】 何桢；

【作者基本信息】 天津大学 ， 管理科学与工程， 2007， 硕士

【摘要】 统计过程控制技术目前是生产过程中控制稳定产出的主要工具,在生产型企业中应用的非常广泛。传统的统计过程控制理论是基于正态分布这个基本假设的,而在实际生产过程中大量非正态过程传统SPC技术会失效。目前非正态过程能力指数的构建与评价研究是过程能力研究中的热点问题。本文首先介绍了过程能力指数的基础理论和知识以及非正态过程能力研究的一些问题,并描述了非正态过程处理的实施步骤。接着详细探讨非正态过程能力研究的重要转换方法——Johnson转换和Box-Cox转换方法,并对这两种方法进行了比较分析。结合案例应用对Johnson转换的最佳转换参数进行了研究,还对过程能力指数的估计效果进行评价,即拟合有效性检验问题。这些方法可以用于指导生产实践。另外,本文还介绍了其他的转换方法和非正态过程能力的两个新指数,以及非转换方法——修正的加权方差方法估算非正态过程能力指数。以上这些方法都是为了更好的处理现实生产过程中的非正态现象,对于实践具有重要意义。本文以非正态过程能力分析理论为主线,运用统计学原理、数学推导、比较分析和实证研究方法对非正态过程能力指数进行了详细的分析探讨,对不同的非正态过程能力评价方法进行理论研究和实证分析,构建了系统的非正态过程能力指数评价体系。更多还原

【Abstract】 Statistical process control (SPC) is one of the main tools for controlling processes and widely used in the manufacturing industry. Traditional SPC theory is based on a fundamental assumption that the process data are normal. However, in many conditions the process data are non-normal which makes traditional SPC theory invalid. Therefore, the study on construction and appraisal of process capability index for non-normal processes is a hot issue to be solved.This paper firstly introduces the basic theory and knowledge of process capability index and some issues in the study of non-normal process capability and describes how to handle non-normal processes. Then it discusses some important transformation methods for non-normal process capability, which are Johnson transformation and Box-Cox transformation methods, and does some competitions with these two methods. Study on the best transformation parameter has been done by analyzing some cases. All of these methods can be used directly in practice. This paper also introduces some other transformation methods, two new process capability indexes for non-normal processes and non-transformation methods——corrected weighted variance method. All these methods can contribute to the practice and do well to the non-normal processes.The paper is based on the main line of process capability analysis methods for non-normal processes. Statistics principle, mathematics derivation, comparative analysis and case study are employed to carry out the thorough examination to the theory of process capability analysis and control methods for non-normal processes. All of these construct a systematic evaluation for capability index for non-normal processes.更多还原