Page 352 - Six Sigma Advanced Tools for Black Belts and Master Black Belts
P. 352

OTE/SPH
 OTE/SPH
                         3:7
                              Char Count= 0
 JWBK119-21
          August 31, 2006
                                   Numerical Examples                        337
                                                               5
      Table 21.6 A set of data for a simulated process (from Table I, Xie et al. ).
      Nonconforming          Simulation   Nonconforming           Simulation
      no.             CCC    legend            no.         CCC    legend
       1              3 706  p = 500 ppm        16          753   p = 500 ppm
       2              9 179  p = 500 ppm        17         3 345  p = 500 ppm
       3                78   p = 500 ppm        18          217   p = 500 ppm
       4              1 442  p = 500 ppm        19         3 008  p = 500 ppm
       5               409   p = 500 ppm        20         3 270  p = 500 ppm
       6              3 812  p = 500 ppm        21         5 074  Shift, p = 50 ppm
       7              7 302  p = 500 ppm        22         3 910  p = 50 ppm
       8               726   p = 500 ppm        23        23 310  p = 50 ppm
       9              2 971  p = 500 ppm        24        11 690  p = 50 ppm
      10                42   p = 500 ppm        25        19 807  p = 50 ppm
      11              3 134  p = 500 ppm        26        14 703  p = 50 ppm
      12              1 583  p = 500 ppm        27         4 084  p = 50 ppm
      13              3 917  p = 500 ppm        28          826   p = 50 ppm
      14              3 496  p = 500 ppm        29         9 484  p = 50 ppm
      15              2 424  p = 500 ppm        30        66 782  p = 50 ppm




      and the estimate before suspension (154 ppm), all data are combined. Estimation
      is suspended again at M = 10 and for similar reason; the estimation is resumed at
      M = 20. At M = 22, as there are four consecutive points plotted above the center line,
      estimation is suspended again.
        The23rdobservationisplottedabovetheUCL,indicatingpossibleprocessimprove-
      ment. Thus, by using the proposed sequential estimation scheme with the guidelines
      given, the CCC chart with estimated parameter is as effective as that constructed
      assuming known p in detecting a change in p.


            100000.00


             10000.00


              1000.00


               100.00


                10.00


                 1.00
                     0       5       10       15       20      25       30
          Figure 21.4  CCC chart when p 0 is known (= 500 ppm) and in-control ARL = 200.
   347   348   349   350   351   352   353   354   355   356   357