【正文】 chart with data amp。 new control limits – Do the limits detect known problems? – 界限可以查覺已知的問題嗎 ? – Are the limits too sensitive? Would they flag problems you do not know how to react to? – 界限是否太敏感 ? 是否有問題你不曉得如何處理 ? ? Use the control limits established to monitor the critical parameter identified ? 使用建立的管制圖來追蹤確認(rèn)重要參數(shù) ? For each parameter, every machine should have a separate control chart with separately puted control limits ? 對每一參數(shù) , 每臺機(jī)器應(yīng)有一獨(dú)立的管制圖與管制界限 How to Setup a Control Chart? (III) 174。 Materials Quality PCS Training Rev 3 May 21 2022 13 Control Chart Classifications 類型 Classifications of control charts are depending on the type of data 依數(shù)據(jù)型態(tài)可分類為 : ? Variables data 計量型數(shù)據(jù) – A characteristic measured on a continuous scale resulting in a numerical value 特性 : 連續(xù)性 ,可量測 ,有小數(shù)點(diǎn) – Examples: Void Size, Bond Pull Strength, Coplanarity, Ball Height, etc. 如尺寸 ,推拉力 ,平面度 ,高度 ? Attributes data 計數(shù)型數(shù)據(jù) – A characteristic measured by of conforming amp。 nonconforming to a specification. Output is classified as pass/fail or accept/reject. 特性 : 計數(shù)的 ,合格 /不合格 , – . Broken Wire, Lifted Bond, FM, Chipping, Bent Lead, etc. 如 : 故障數(shù) , – Can be expressed in terms of fraction, percentage, count or DPM 以分?jǐn)?shù) ,百分比 ,DPM單位表示 174。 Materials Quality PCS Training Rev 3 May 21 2022 14 Control Chart When to Use (Guidelines only)? XS when subgrouping of samples or (MeanStandard Deviation) Chart measurements is applicable n = 10 n=10 X when subgrouping is not applicable (Individual) due to single unit reading may take Chart a long time, unit reading is extremely expensive, etc. when it39。s mon to have single measurement spaced time apart Control Charts For Variables 計量型 每次量測費(fèi)時或昂貴 ,使同一段時間內(nèi)量測多次不適當(dāng) 每次量測值都非常相近 ,同一段時間內(nèi)量測多次 174。 Materials Quality PCS Training Rev 3 May 21 2022 15 Why MR Method is used to determine Control Limits for Mean amp。 Variability (Range amp。 Standard Deviation) Chart? 為什麼要使用移動全距方法 ? ? Most batch production processes have a larger runtorun variation than withinrun variation 批量性生產(chǎn)時 ,子群組間的變異大多會大於子群組內(nèi)的變異 ? Traditional control chart formulas developed in the 20?s by Walter Shewhart considerably underestimate control limits, . too narrow 傳統(tǒng)的方法將使管制界限太窄 174。 Materials Quality PCS Training Rev 3 May 21 2022 16 Traditional vs. MR Method Traditional control chart formulas are used. Moving Range (MR) Method is used. Xbar Control Chart Xbar Control Chart 174。 Materials Quality PCS Training Rev 3 May 21 2022 17 X S Chart Concept Consists of Two Portions: – X Chart 187。 Plots the mean of the X values in the sample 187。以抽樣的平均值描點(diǎn) 187。 Shows the changes of the mean of one sample to another 187。顯示抽樣平均值的改變 – S Chart 187。 Plots the standard deviation of a sample 187。以抽樣的標(biāo)準(zhǔn)差描點(diǎn) 187。 Shows the changes in dispersion or process variability of one sample to another 187。顯示抽樣標(biāo)準(zhǔn)差的改變 174。 Materials Quality PCS Training Rev 3 May 21 2022 18 Computing Control Limits for X S Chart ? Obtain at least k = 30 subgroups ? 獲得至少 30組子群組 ? Compute the Mean for each subgroup of size n ? 計算每子群組 (個數(shù) n)的平均值 ? Compute the Standard Deviation for each subgroup ? 計算每子群組 (個數(shù) n)的標(biāo)準(zhǔn)差 ? Compute the Moving Range for each subgroup mean, MRXi = | Xi Xi1 | ? 計算每子群組平均值的移動全距 ? Compute the Moving Range for each subgroup range, MRSi = | Si Si1 | ? 計算每子群組標(biāo)準(zhǔn)差的移動全距 174。 Materials Quality PCS Training Rev 3 May 21 2022 19 Computing Control limits for X S Chart ? Compute the Overall Mean, X = (X1 + X2 + X3 ... + Xk) / k ? Compute the Average of Range, S = (S1 + S2 + S3 ... + Sk) / k ? Compute the Average of Moving Range for the mean, MRX = (MRX2 + MRX3 + MRX4 ... + MRXk) / (k 1) ? Compute the Average of Moving Range for the range, MRS = (MRS2 + MRS3 + MRS4 ... + MRSk) / (k 1) = 174。 Materials Quality PCS Training Rev 3 May 21 2022 20 ? Compute the Control Limits: ? Draw the control limits on both the X S chart respectively ? If LCL (S) 0, put as 0 or N/A X Chart 187。UCL (X) = X + 187。CL (X) = X 187。LCL (X) = X = = = Computing Control limits for X S Chart S Chart 187。UCL (S) = S + 187。CL (S) = S 187。LCL (S) = S 174。 Materials Quality PCS Training Rev 3 May 21 2022 21 Observations Mean Moving Range S. D. Moving Range Subgroup 1 2 3 4 5 (X bar) (MRX ) (S) (MR S ) 1 2 3 : : 30 Average ? X Chart UCL (X) = X + = + () = CL (X) = X = LCL (X) = X = () = Example of Computing Control Limits for X S Chart ? S Chart UCL (S) = S + = + () = CL (S) = S = LCL (S) = S = () = 174。 Materials Quality PCS Training Rev 3 May 21 2022 22 Open the dataset . 1. Compute the mean for each lot. ? Select Summary from the Tables menu. ? Select Lot as the Group variable. ? Highlight Thickness amp。 select Mean from the Statistics menu. Then, highlight Thickness amp。 select Std Dev from the Statistics menu. ? Click OK. 2. Create an individuals control chart using the table of lot means amp。 ranges. ? Select Control Chart from the Graph menu. ? Select Mean(thickness) amp。 StdDev(Thickness) as the Process variable. ? Select Lot as the Sample Label variable. Verify option settings. ? Chart Type is “IR”. ? Individual Measurement box is selected. ? Moving Range box is not selected. ? Ksigma is selected, and K = 3. ? Range Span = 2. Click on OK. Example of Computing Control Limits for X S Chart using JMP 174。 Materials Quality PCS Training Rev 3 May 21 2022 23 WARNINGS: Group / Summary will sort the new table in alphabetical order of the groupi