【正文】 1 3 . 5 9 0 % 2 . 1 4 5 % 0 . 1 3 5 %4 3 2 1 0 1 2 3 46 8 . 2 6 %9 5 . 4 4 %9 9 . 7 3 %174。 Materials Quality PCS Training Rev 3 May 21 2022 35 Caution When Using MR Method ? If there is autocorrelation, MR(Summary Stat) will underestimate the true process variation amp。 the number of units containing undissolved flux were recorded over several lots. Make a p Chart for Undissolved Flux Interpret the control chart 174。LCL (p) = p ? When LCL 0, put LCL = 0 or N/A ? Draw the control limits on p chart 174。 Materials Quality PCS Training Rev 3 May 21 2022 29 Computing Control Limits for p Chart with MRMethod ? Obtain at least k = 30 subgroups or lots. Data collected in of units inspected amp。 Materials Quality PCS Training Rev 3 May 21 2022 25 Interpretation of X S Chart Some special causes of outofcontrol for ? X Chart – Changes in machine setting or adjustment – 參數(shù)設定被調整 – MStoMS technique inconsistent – Changes in material – 材料變化 ? S Chart – Machine in need of repair or adjustment – 機器須維修 – New Mses – Materials are not uniform – 材料一致性不夠 174。 ranges. ? Select Control Chart from the Graph menu. ? Select Mean(thickness) amp。 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。LCL (X) = X = = = Computing Control limits for X S Chart S Chart 187。 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。以抽樣的標準差描點 187。以抽樣的平均值描點 187。 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 批量性生產時 ,子群組間的變異大多會大於子群組內的變異 ? 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 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。 Materials Quality PCS Training Rev 3 May 21 2022 12 ? Validate the puted control limits against data collected by replotting the control chart with data amp。 Materials Quality PCS Training Rev 3 May 21 2022 10 ? Select appropriate type of control chart to be used ? 選擇合適的管制圖型態(tài) ? Gather data to establish the control chart. ? 收集數(shù)據建立管制圖 – A minimum of 30 subgroups is required over a time frame as determined by the sampling plan. – 抽樣計劃至少收集 30組數(shù)據 ? Plot the data in time order on a Trend Chart ? 依序在趨勢圖上描點 How to Setup a Control Chart? (I) 174。 LCL: 制程穩(wěn)定情況下 , 制程性能的範圍 174。 Materials Quality PCS Training Rev 3 May 21 2022 6 What is a Control Chart? ? A trend chart with control limits ? 有管制界限的趨勢圖 ? Graphical representation of process performance, where data is collected at regular time sequence of production ? 數(shù)據依生產順序定時間收集 ,以圖表表現(xiàn)制程性能 ? Valuable tool for differentiating between mon cause and special cause variation ? 將一般變異與特殊變異區(qū)分開的有用工具 ? Evaluating whether a process is or is not in a state of statistical control ? 評估制程是否在統(tǒng)計管制中 ? It lets the data ?talk? by itself amp。 improve process capability. 174。 Materials Quality PCS Training Rev 3 May 21 2022 4 What is SPC? ? Statistical 統(tǒng)計 – Anything that deals with the collection, analysis, interpretation amp。174。 Materials Quality PCS Training Rev 3 May 21 2022 3 Contents ? Introduction 簡介 – What is SPC 什麼是 SPC? – What is Stability 什麼是穩(wěn)定性 ? ? What is a Control Chart 什麼是管制圖 – How to Setup a Control Chart 如何建立管制圖 – Type of Control Charts Available 管制圖的種類 – How to Calculate the Control Limits 如何計算管制界限 – SPC Trend Rules SPC法則 – When to Revise Control Limits 何時重新計算管制界限 ? Process Capability Study 制程能力研討 – Spec limits VS Control Limits 規(guī)格界限 vs. 管制界限 – Stability VS Capability 穩(wěn)定性 vs. 能力 ? Control Chart Reduction/Elimination 減少管制圖 ? SPC Expectations 174。 maintain a stable process, amp。 manufacturing personnel – 提高生產性 – Predictable, repeatable results within a specified range – 結果有重覆性 ,可預測 174。 LCL: The range of ?usual? process performance when the process is stable. Lines drawn 3 standard deviations (3 sigma) on each side of the center line. UCL amp。 Materials Quality PCS Training Rev 3 May 21 2022 9 Test for Control Chart Assumptions 假設 ? Process Stability (no outliers) 穩(wěn)定性 – Screen out outliers from the database before puting final control limits by using a control chart. Any point beyond either control limit is an outlier. Report number of outliers screened. 計算管制界限前 ,將超出點排除 . 所有超出管制界限的點都是 outlier ? Normality 常態(tài)性 – Plot a normal probability plot of the data or overlay a normal curve over the histogram. Normally distributed data will roughly fall on a straight line. – Test for normality by