【導(dǎo)讀】Location:Notes:\\…BennyMatthiassen(NMPCMT,Copenhagen,Denmark). FrankAdler(NMPAlliance,Dallas,USA). JoniLaakso(NMPR&D,Salo,Finland). JimChristy(NMPSRC,Southwood,UK). .millimetres,volts,amps,decibelandseconds.scratches(visualquality).Allprocesseshave:. StableProcess:. UnstableProcess:. CommonCauses:. (DOE),etc.SpecialCauses:. 10,8?0,1. dimension.

　　

【正文】 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 Exercise 2: Cp and Cpk ? Calculate Cp and Cpk for the 100 measurements in the file Data exercise ? Determine the approximate Cp and Cpk for the 4 sample populations on the following page ? Should actions be made to improve these processes. If yes, which? 39 169。 NOKIA 2001 Estimate Cp and Cpk? The width of the normal distributions shown include 177。3*s LSL USL A) LSL USL B) LSL USL C) USL LSL D) 40 169。 NOKIA 2001 Estimate Cp and Cpk? A) LSL USL A) Mean and nominal USL LSL 6*s USL Mean Mean LSL 3*s 41 169。 NOKIA 2001 Estimate Cp and Cpk? B) LSL USL B) Nominal Mean USL LSL 6*s USL Mean Mean LSL 3*s 42 169。 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 Estimate Cp and Cpk? D USL LSL D) Nominal Mean USL LSL 6*s USL Mean Mean LSL 3*s 44 169。 NOKIA 2001 Section 4. Use of the NMP Data Collection Spreadsheet 45 169。 NOKIA 2001 Example of how to Collect Data 1. Run in and stabilise process 2. Note the main parameters for reference 3. When the process is stable run the tool for 10 hours 3. Take 5 parts out from each cavity every half hour and mark them with time, date and cavity. Total 20 sets of 5 parts from each cavity must be made, or according to agreement. 4. After the last sample lot note the main process parameters for reference 5. Measure and record the main functional characteristics (white diamonds) 6. Fill data into the NMP data collection spreadsheet 7. Analyse! Time Dimension Subgroup size n = 5 Number of subgroups N = 20 0,5 hours between samples taken Note: For clarity, only 6 subgroups are shown 46 169。 NOKIA 2001 Data Collection Sheet () 47 169。 NOKIA 2001 Data Collection Sheet () 48 169。 NOKIA 2001 Graphical Presentation: Histogram ? What kind of distribution? Location versus tolerance area Width (deviation) ? Example : Cp Pp ? Cpk Ppk 49 169。 NOKIA 2001 Graphical Presentation: Xbar and RChart XBar Chart RChart 50 169。 NOKIA 2001 Graphical Presentation Time Series Plot Something happened here !!! 51 169。 NOKIA 2001 Exercise 3: Cpk Data Spreadsheet ? Open spreadsheet Data exercice . Dim 13 is identical to the data from the previous exercises. ? Verify the results from the previous exercises for dimension 13. ? Analyse the remaining data sets an ment the process, should any actions be made? Remember to create and look at the charts. 52 169。 NOKIA 2001 Section 5. Confidence of Cpk 53 169。 NOKIA 2001 Confidence of Cpk ? Cpk values are not definite numbers as they are based on relatively small samples of a population. ? The 95% confidence interval determines the interval which includes the true Cpk value with a probability of 95%, . there is a probability of 5% that Cpk is either lower or higher than this confidence interval. 95% confidence interval Actual cpk Cpk upper confidence limit Cpk lower confidence limit 54 169。 NOKIA 2001 Confidence of Cpk 9 5 % C on f i de nc e I nt e r v a l on a C pk of 1 . 6 70 . 0 0 00 . 5 0 01 . 0 0 01 . 5 0 02 . 0 0 02 . 5 0 03 . 0 0 03 . 5 0 00 50 100 150 200 250S a m p l e S i z eCpkC p k . LC p k . USmall sample sizes gives wide confidence intervals 55 169。 NOKIA 2001 Cpk Confidence Limits with a sample size of 100 and a nominal Cpk of