【正文】 ple mean Process variation 6*s stp sL SLU SLC*6? USLLSL LSL USL Nominal dim ltp sL SLU SLP*6?The tolerance area divided by the total process variation, irrespective of process centring. 30 169。 NOKIA 2001 Cp and Cpk Indices and Defects (both tails of the normal distribution) C pk/ P pkC p/ P p0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0 . 6 0 . 7 0 . 8 0 . 9 1 . 0 1 . 1 1 . 2 1 . 3 3 1 . 4 1 . 5 1 . 6 7 2 . 0 2 . 5 3 . 0 4 . 0 % / P P M0 . 1 7 6 . 4 2 5 6 . 6 1 4 4 . 8 9 4 0 . 0 0 3 8 . 5 6 3 8 . 2 6 3 8 . 2 1 3 8 . 2 1 3 8 . 2 1 3 8 . 2 1 3 8 . 2 1 3 8 . 2 1 3 8 . 2 1 3 8 . 2 1 3 8 . 2 1 3 8 . 2 1 3 8 . 2 1 3 8 . 2 1 3 8 . 2 1 3 8 . 2 1 %0 . 2 5 4 . 8 6 3 8 . 9 3 3 1 . 0 2 2 8 . 2 5 2 7 . 5 6 2 7 . 4 4 2 7 . 4 3 2 7 . 4 3 2 7 . 4 3 2 7 . 4 3 2 7 . 4 3 2 7 . 4 3 2 7 . 4 3 2 7 . 4 3 2 7 . 4 3 2 7 . 4 3 2 7 . 4 3 2 7 . 4 3 2 7 . 4 3 %0 . 3 3 6 . 8 1 2 5 . 0 9 2 0 . 1 9 1 8 . 7 5 1 8 . 4 5 1 8 . 4 1 1 8 . 4 1 1 8 . 4 1 1 8 . 4 1 1 8 . 4 1 1 8 . 4 1 1 8 . 4 1 1 8 . 4 1 1 8 . 4 1 1 8 . 4 1 1 8 . 4 1 1 8 . 4 1 1 8 . 4 1 %0 . 4 2 3 . 0 1 1 5 . 1 0 1 2 . 3 3 1 1 . 6 4 1 1 . 5 2 1 1 . 5 1 1 1 . 5 1 1 1 . 5 1 1 1 . 5 1 1 1 . 5 1 1 1 . 5 1 1 1 . 5 1 1 1 . 5 1 1 1 . 5 1 1 1 . 5 1 1 1 . 5 1 1 1 . 5 1 %0 . 5 1 3 . 3 6 8 . 4 7 7 . 0 3 6 . 7 3 6 . 6 9 6 . 6 8 6 . 6 8 6 . 6 8 6 . 6 8 6 . 6 8 6 . 6 8 6 . 6 8 6 . 6 8 6 . 6 8 6 . 6 8 6 . 6 8 %0 . 6 7 . 1 9 4 . 4 1 3 . 7 3 3 . 6 1 3 . 5 9 3 . 5 9 3 . 5 9 3 . 5 9 3 . 5 9 3 . 5 9 3 . 5 9 3 . 5 9 3 . 5 9 3 . 5 9 3 . 5 9 %0 . 7 3 . 5 7 2 . 1 3 1 . 8 3 1 . 7 9 1 . 7 9 1 . 7 9 1 . 7 9 1 . 7 9 1 . 7 9 1 . 7 9 1 . 7 9 1 . 7 9 1 . 7 9 1 . 7 9 %0 . 8 1 . 6 4 0 . 9 5 0 . 8 4 0 . 8 2 0 . 8 2 0 . 8 2 0 . 8 2 0 . 8 2 0 . 8 2 0 . 8 2 0 . 8 2 0 . 8 2 0 . 8 2 %0 . 9 0 . 6 9 0 . 4 0 0 . 3 5 0 . 3 5 0 . 3 5 0 . 3 5 0 . 3 5 0 . 3 5 0 . 3 5 0 . 3 5 0 . 3 5 0 . 3 5 %1 . 0 2700 1509 1363 1350 1350 1350 1350 1350 1350 1350 1350 PPM1 . 1 967 532 485 484 483 483 483 483 483 483 PPM1 . 2 318 165 160 159 159 159 159 159 159 PPM1 . 3 3 63 38 33 33 32 32 32 32 PPM1 . 4 27 14 13 13 13 13 13 PPM1 . 5 7 3 3 3 3 3 PPM1 . 6 7 0 . 6 0 . 3 0 . 3 0 . 3 0 . 3 PPM2 . 0 0 . 0 0 . 0 0 . 0 0 . 0 PPM2 . 5 0 . 0 0 . 0 0 . 0 PPM3 . 0 0 . 0 0 . 0 PPM4 . 0 0 . 0 PPMPp=Ppk=1,33 ? 63 ppm defects = 0,006% Cp=Cpk=1,67 ? 0,6 ppm defects = 0,00006% Note: Ppm reject rates calculated from Cp amp。 NOKIA 2001 Estimate Cp and Cpk? C) LSL USL C) Nominal Mean USL LSL 6*s USL Mean Mean LSL 3*s 43 169。 NOKIA 2001 Graphical Presentation Time Series Plot Something happened here !!! 51 169。 NOKIA 2001 Section 5. Confidence of Cpk 53 169。 NOKIA 2001 Section 4. Use of the NMP Data Collection Spreadsheet 45 169。 NOKIA 2001 The Effects of Cpk and Cp on FFR C p k Cp Pp m d e f e c t sT o t a l n u m b e r o f d e f e c t s f o r 5 0 , 0 0 0 , 0 0 0 p a rt sT o t a l n u m b e r o f d e f e c t s i f p h o n e h a s 1 0 o f t h e s e p a rt s0 . 8 1 . 3 3 8 , 2 0 0 4 1 0 , 0 0 0 4 , 1 0 0 , 0 0 01 1 . 3 3 1 , 3 5 0 6 7 , 5 0 0 6 7 5 , 0 0 01 . 3 3 1 . 3 3 63 3 , 1 5 0 3 1 , 5 0 01 . 3 3 1 . 6 7 33 1 , 6 5 0 1 6 , 5 0 01 . 5 0 1 . 5 0 7 350 3 , 5 0 01 . 6 7 1 . 6 7 1 30 3002 . 0 0 2 . 0 0 0 0 138 169。 NOKIA 2001 What is the Difference Between Cp and Cpk? ? The Cp index only accounts for process variability ? The Cpk Index accounts for process variability and centering of the process mean to the design nominal ? Therefore, Cp ? Cpk ? NOTE: Same applies also for Pp and Ppk Cp = Cpk (both low) LSL USL Mean = Nominal Reject parts Reject parts Cp high, Cpk low Process should be optimized! Nominal LSL Mean USL Reject parts 32 169。 NOKIA 2001 ? ? ? ? ? ? ? x3 ? x2 ? x1 ? x10 x _ t 1)(...)()( 222212?????????Nxxxxxxss NLTLT15)()()()()( 22222?????????????LTsExample: What Measurements Can Be Used to Describe Process variation? 24 169。 NOKIA 2001 The Normal Distribution 19 169。 NOKIA 2001 Example of Capability Analysis Da