【正文】 P ) In file , column “voids” contains data for number of parts containing coating voids found at inspection after a coating operation. 在文件 “ voids”列記錄了在涂層操作后的檢測(cè)中發(fā)現(xiàn)的包含無效涂層的零件數(shù)。 Using Minitab, create a PChart of the data. 根據(jù)數(shù)據(jù)在 Minitab中畫出 P圖 What are your observations? What is needed to estimate the Process Capability? 觀察結(jié)論是什么？為估計(jì)過程能力，還需要什么信息？ PChart Minitab Input amp。 Output Minitab中 P圖的輸入和輸出 2 52 01 51 0500 . 0 30 . 0 20 . 0 10 . 0 0S a m p l e N u m b e rProportionP C h a r t f o r V o i d sP = 0 . 0 1 1 9 23 . 0 S L = 0 . 0 2 1 3 7 3 . 0 S L = 0 . 0 0 2 4 7 2Out of controls: determine cause and adjust 失控，確定原因并調(diào)整 Nonconstant control limits due to variable subgroup size 子樣變化引起的控制限不恒定 Very good, determine cause. 非常好，確定原因 Attribute Control Charts 邏輯數(shù)據(jù)控制圖 NPChart (NP圖 ) Selecting the Appropriate Control Chart 選擇適當(dāng)?shù)目刂茍D NPChart (NP圖 ) Variable or Attribute Data? 連續(xù) /邏輯數(shù)據(jù)？ Defects or % Defective 缺陷數(shù) /缺陷百比 Constant Lot Size? 樣本數(shù)不變？ u p No否 Yes是 Defects or Defective 缺陷數(shù) /缺陷百比 c np High or Low Volume 數(shù)據(jù)量大小 Low少 High多 Individuals amp。 Moving Range 個(gè)體和移動(dòng)極差圖 XBar amp。 Range XbarR圖 Variable連續(xù)數(shù)據(jù) Attribute邏輯數(shù)據(jù) NPChart (NP圖 ) ? NPchart: number conforming in subgroup NP圖：子樣大小一致 ? Same logic as the pchart, except constant lot size (n) 除子樣大小 n恒定外，原理同 P圖 NPChart Example NP圖實(shí)例 ? In file , column ―switches‖ contains inspection data from 25 consecutive lots of electrical switches. 在文件 “ switches‖列中記錄了 25組連續(xù) 的電器開關(guān)子樣的測(cè)試數(shù)據(jù) 。 ? The lot size is constant at 100 switches per lot. 子樣大小為每組恒定 100個(gè)電器開關(guān)。 ? Using Minitab, create an NpChart of the data. 根據(jù)數(shù)據(jù)在 Minitab中畫出 NP圖。 ? What are your observations? 觀察結(jié)論是什么？ ? What is the Process Capability? What do you need to know to answer this? 過程能力怎樣？為了回答這一問題，需要做些什么？ NPChart Example： Minitab Menu Commands NP圖實(shí)例： Minitab命令菜單 MINITAB FILE: Np MINITAB文件 : Np NPChart Minitab Input amp。 Output NP圖的 Minitab 輸入和輸出 0 5 1 0 1 5 2 0 2 501 02 0S a m p l e N u m b e rSample CountN P C h a r t f o r s w i t c h e s11N P = 1 0 . 8 03 . 0 S L = 2 0 . 1 1 3 . 0 S L = 1 . 4 8 9Attribute Chart Subgroup Size 邏輯數(shù)據(jù)控制圖的子樣大小 ? Rule of Thumb:拇指規(guī)則 – Select a Subgroup Size that will Provide an Average Defect/Defective Count of Approximately 選擇的子樣大小須能提供大致平均的缺陷數(shù) /缺陷率 To Make UCL amp。 LCL Nearly Symmetrical Around the Mean 為保證 UCL和 LCL大致關(guān)于平均值對(duì)稱 C, U, NP — For NPcharts, to select the appropriate sample size such that 95% of the subgroups will have at least one defective, use the relationship 對(duì) NP圖，為選擇適當(dāng)?shù)臉颖敬笮∫允?95%的子樣會(huì)包含至少一個(gè)缺陷，可使用以下關(guān)系式 pn 3?Summary of Attribute Charts 邏輯數(shù)據(jù)控制圖小結(jié) – Useful when variable data not available 當(dāng)連續(xù)數(shù)據(jù)無法得到是很有用 – Use count/classification data—pass/fail, good/bad 使用諸如合格 /不合格、好 /壞等記數(shù) /分類數(shù)據(jù) – Same general rules for interpretation as variable charts 一些通用規(guī)則與連續(xù)數(shù)據(jù)控制圖相同 – Useful as endtoend overview。 use variable charts for further study of problems 對(duì)分析概況很有用，使用連續(xù)數(shù)據(jù)控制圖對(duì)問題可做進(jìn)一步研究 – Can use data gathered for other purposes 可使用為其它目的收集的數(shù)據(jù) – Generally less expensive to administer, but tell you less 通常需要較少資源管理，但得到的信息亦較少 Summary of Attribute Charts 邏輯數(shù)據(jù)控制圖小結(jié) ? Shortings 缺點(diǎn)： – Including too many variables makes interpretation difficult 包含太多變量，使解釋較為困難 – Must fit the parameters you are evaluating to theoretical distribution [Poisson (C, UCharts), Binomial (P, NPCharts)] 必須滿足所評(píng)估的參數(shù)的理論分布 (C圖 U圖泊松分布、 P圖 NP圖二項(xiàng)式分布 ) – Need to evaluate whether constant/nonconstant lot size will help you with root cause analysis 須評(píng)估子樣大小是否恒定對(duì)根本原因分析的影響 – Sensitivity is dependent on magnitude of defect level 敏感性取決于數(shù)量和缺陷水平 Take Aways—Attribute Control Charts 邏輯數(shù)據(jù)控制圖小結(jié) ? Attribute control charts are used to monitor the level of nonconformance of a process. 邏輯數(shù)據(jù)控制圖用來監(jiān)控過程不合格品的水平 ? Select the appropriate attribute control chart based upon 根據(jù)以下兩項(xiàng)選擇適當(dāng)?shù)倪壿嫈?shù)據(jù)控制圖 – constant vs. variable lot size子樣大小是否恒定 – defects vs. defectives缺陷數(shù) /缺陷率 ? Defect (缺陷 ) – A single characteristic that does not meet requirements 不滿足要求的單一特性 ? Defective (缺陷率 ) – A unit that contains one or more DEFECTS 包含單個(gè)或多個(gè) 缺陷 的單位