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Process Sampling – short term 过程抽样－短期
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Process Sampling – short term 过程抽样－短期
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Process Sampling – Short Term / Long Term 过程抽样－短期/长期
6σ
6σ
A Very, Very Capable Process 制程能力非常充分
σ =0.04
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Sigma Level Sigma 水平 3σ Process
4σ Process
6σ Process
Customer Requirement and capability 能力与客户要求
By Strive Zhou
By Strive Zhou
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Short-term or Long-term 短期还是长期？
➢ Another may is though observation: 另外一个方法可用来观察
k
j 1
m i 1
Yij
y
2
k j 1
n
j
Yi
y
2
k j 1
m i 1
Yij
y
2
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What brings defects? 什么导致缺陷？
Unstable incoming material 不稳定的原材料
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Inappropriate specification design 不适当的规格设计
Poor process Capability 不充分的制程能力
Frequency
Process Capability – Variable Data 制程能力－－－计量型数据
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Variable Output: The Method 计量输出：方法
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Step 1: Check Specification 步骤1：规格确认
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How Capable Is It? 制程能力如何？
USL LSL
3σ 3σ 4σ 4σ
Capable Process 制程能力充分
A Very Capable Process
制程能力很充分
USL LSL
Standard Deviation
标准差 σ =0.08
σ =0.06
USL LSL
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Capability Analysis 制程能力分析
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Process capability analysis using different Types of data 使用不同类别数据进行制程能力分析
Variable 计量型
Attribute 记数型
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8
9
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Step 2: Sample Data-Rational Grouping 步骤2：采集数据－合理分组
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Step 2: Sampling 步骤2：取样
♣ Eg. The engineer takes 5 data a day for consecutively 7 days.
Capability Analysis 能力分析
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Process Improvement Methodology 制程改善方法论
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What is Capability 制程能力是……
When process is under control, capability is decided by customer demand and process performance (product or service quality shifting degree), The more the process meets the customer need, the better the capability will be. 制程在受控状态下时，客户要求与制程表现（产品品质或服务的品 质变动程度）的比值，如果制程表现越能满足客户要求，则制程能 力越充分，反之则不足。
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Example-Short Term Shift 短期波动的例子
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Example-Short Term Shift 短期波动的例子
❖ Calculate short term shift (with Minitab) 使用Minitab来计算短 期波动
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Short-term or Long-term 短期还是长期？
Opportunity 机会
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Short-term or Long-term 短期还是长期？
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Short-term or Long-term 短期还是长期？
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使用许多机器
❖ Analyzing the performance of many operators 许多操作者
❖ Using many lots of incoming parts 使用多批原材料
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Process Sampling –Long Term 过程抽样－/长期
LSL
USL
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What is Capability 制程能力是……
A
C
LSL
USL
LSL USL
B
D
What can we conclude form the capability of these process? 这些制程的制程能力 如何？
LSL USL
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LSL USL
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How Capable Is It? 制程能力如何？
6σ
LSL
USL
Capable Process
制程能力充分
6σ
6σ
By Strive Zhopable Process
制程能力很充分
LSL A Very, Very USL Capable Process 制程能力非常充分
Data collected from Rational Grouping Samples. 快速凭票采集的数据应从合理分组中抽样
O o o oo o O oo o
O oo o o o O oo oo o O o o oo o
O o oo oo O oo o o o O oooo o
0
1
2
3
4
5
6
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Example 举例
Pen. mtv
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Step 1: Check Specification 步骤1：规格确认
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Step 2: Sample Data-Rational Grouping 步骤2：采集数据－合理分组
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Process Sampling –Long Term 过程抽样－/长期
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Process Sampling –Long Term 过程抽样－/长期
❖ From many shifts of production
从许多生产班次而来
❖ Observing many machines
Sigma Level Sigma 水平
1 2 3 4 5 6
Short-term DPMO 短期的DPMO
158655.3 22750.1
1350 31.7 0.3 0.0
Long-Term DPMO 长期的DPMO
691462.5 308537.5 66807.2
6209.7 232.7
3.4
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♣ Data collected should be able to reflect term and long term performance (if possible) 数据采集应能捕捉过程的短期绩效和长期绩效（若有可能）
➢ Data can be collected within a short period of time and arranged in a time sequence. 可通过快速采集一系列数据来完成，这些数据按照时间序列排列；
通常，长期与短期的 Sigma 水平1.5 σ
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Long-term and short-term capability (Zshift) 长期和短期能力（Z－偏差）
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Long-term and short-term capability (Zshift) 长期和短期能力（Z－偏差）
❖ Stat>Quality Tools>Capability analysis (Normal)
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Step3: Calculate Zu and Z1 步骤3：计算Zu和Z1