SPC (统计过程控制)training.ppt

* SPC SPC Implement SPC in work shop Introduction to SPC SPC简介 ? SPC is the basic tool for studying variation and using statistical signals to monitor and/or improve process performance. This tool can be applied to ANY area: Manufacturing, Finance, Sales, etc… SPC是研究过程变化的基本工具，它使用统计信号来监测和/或提高过程性能。该工具可应用于任何领域：制造，财务，销售等。 ? SPC is an acronym for Statistical Process Control. Most applications perform SPC on product characteristics (Y’s), rather than process characteristics (X’s) SPC是“Statistical Process Control(统计过程控制）”的首字母缩写。SPC大部分被用于控制产品的特性而不是过程的特性 ? The first step is to use statistical techniques to control our process outputs. However, it is not until we focus our efforts on controlling those inputs (X’s), rather than control our outputs (Y’s), that we realize the full gain of our efforts to increase quality, productivity, and lower costs. 第一步就是用统计技术去控制过程输出。然而，如果只控制过程的输出，而不控制过程的输入，我们就无法体验到SPC在提高质量，提高生产力及降低成本等方面的诸多好处。 What is Statistical Process Control 什么是统计过程控制？ ? All processes have natural (expected) variability (due to common causes) and sometimes unexpected variability (due to special causes). We use SPC to monitor (and improve) our processes. Use of SPC allows us to DETECT special cause variation through OUT-OF-CONTROL signals. These out of control signals CAN NOT tell us WHY the process is out of control, only that it is.所有过程都具有自然的(预料中的）变化（由普通原因造成）和临时发生的意料之外的变化（由特殊原因造成）。可以使用SPC来监控（并改善）我们的过程。使用SPC能够通过失控信号来检测出特殊原因变量。这些失控信号仅能告诉我们过程失控，并不能告诉我们为什么过程会失控。 ? CONTROL CHARTS are the means through which process and product parameters are tracked statistically over time. Control charts incorporate upper and lower control limits that reflect the natural limits of random variability in the process. These limits should NOT be compared to customer specification limits.控制图是一种随时间从统计学角度跟踪过程及产品参数的方法。控制图中的上、下控制界限能够反映过程中随机变化的内在界限。控制界限不能与顾客要求的规格界限相比较。 ? Based on statistical principles, control charts allow for the identification of unexpected (nonrandom) patterns in process variation.