【正文】
) % (57 ppm) % Well Problem Solving Approach Center Process Reduce Spread X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X OffTarget Unpredictable OnTarget 6? Helps us Identify and Reduce VARIATION due to: Insufficient Process Capability Unstable Parts Materials Inadequate Design Margin Well Target USL LSL Target USL LSL Target USL LSL Center Process Reduce Spread OffTarget Unpredictable OnTarget Defects Problem Solving Approach “ Lower Specification Limit” “ Upper Specification Limit” Less Variation Means Fewer Defects Higher Process Yields Well 6?有多小 ? Sigma ?? ?? ?? ?? ?? ?? PPM 2,700 45,500 317,310 面積 一般教室 2倍 約 6甲地 約 30個(gè)中正紀(jì)念堂 略大於臺(tái)北市 臺(tái)北縣的兩倍半 臺(tái)灣省的面積 時(shí)間 1 秒鐘 分鐘 9 小時(shí) 半個(gè)月 約 9 個(gè)月 5 年 Well 6?的四個(gè)假設(shè) 常態(tài)分配 177。?偏移 ?和 ?已知 缺點(diǎn)乃隨意分佈,且不同零件及製程相互獨(dú)立 Well 偏移177。 ? 在動(dòng)態(tài)的真實(shí)世界中,每一件事都在不停的變化著 溫度 溼度 工具的磨耗 原料的差異 ...... ?乃由機(jī)率、估計(jì)、經(jīng)驗(yàn)而來 參考資料 :Evans, . (1975) : Statistical Tolerancing : The State of the Art, Part III. Shifts and Drifts. Well U S LL S L? ? ?3 . 4 p p m~ 0 p p m+ 1 . 5 ? s h i f t 0 ????p r o c e s sc a p a b i l i t y ? Well 6?的品質(zhì)水準(zhǔn) ppm , Cp=2 中心值 177。?的偏移 ppm, Cpk= 或用 npmo (nonconformities per million opportunities)表示 Well specific ati on w idth( ∮ sigma)0 .0 0 10 .0 10 .11101001000100001000002 3 4 5 6 7∮ 1 .5 S i g maSh i fte dCe n t e redrelativenumberofdefects(ppm) Well Sigma DPMO Yield Sigma DPMO Yield 6 13 21 32 48 72 108 159 233 337 483 687