过程能力研究--邹道贵.pptVIP

能力分析 Capability Studies 是什么导致了缺陷? What Causes Defects? 过度的变异是由于Excess Variation due to: 制造流程 Manufacturing Processes 供应商材料的变化 Supplier Material Variation 不合理的规格(比客户的要求还要严格) Unreasonably Tight Specifications (Tighter than the Customer Requires) 了解流程能力Understanding Process Capability 能力分析的类型 Types of Capability Studies 能力指数 Capability indices 计量型数据, 数据正态稳定, 知道客户的要求 Variables, data are normal and stable, customer specification known 西格玛计算方法 Sigma calculator 计量型或属性型 Variables or attribute 在某一时间点,数据不稳定时是有用的 One point in time, useful when data are not stable 属性能力分析 Attribute capability study 以往定性数据表现情况 Attribute data performance over time 控制图 Control charts 客户的规格限制没有被指定说明 Customer specification limits are not specified 能力指数 Capability Index 可见的流程能力Visualizing Process Capability 是否流程偏离了目标If the Process is Off Target 更大的设计余量能带来更好的累计产出率 The greater the design margin, The better the Rolled Throughput Yield 能力分析中的统计假设 Statistical assumptions made in Capability Studies 数据来自稳定的流程 Data comes from a stable process 如果不是, 先尽量控制流程 If not, work toward getting the process in control 别失望, 这样你可以在流程上有很大的提高 Don’t despair, you can make big improvements in processes like these. 2. 正态分布 Has a Normal Distribution 如果没有,找个可替代的能力测量方法(我们一会再介绍) If not, use alternative capability measure (we will cover this later in the course) 如果假设1和2不能满足,结果将被误导. Minitab的能力6项会帮你检查这些假设. If items #1 and #2 aren’t met, results will be misleading. Minitab’s capability Sixpack helps you check these assumptions 能力实例 Capability Example 能力: 稳定性检查 Capability: Check Stability 能力: 平均数和标准方差Capability: Mean Standard Deviation MINITAB 能力分析: 统计等候时间Minitab Capability Study: ST Wait Time Minitab 能力分析:统计等候时间Minitab Capability Study: ST Wait Time Minitab 能力分析:统计等候时间Minitab Capability Study: ST Wait Time 能力分析结论 Capability Analysis Conclusions 能力分析(正态) From the “Capability Analysis (Normal) 流程基本是居中的 The process is almost centered 流程形态是正态的 The process shape is normal 流程分散程度比规格要窄 The proces