a) a manager states that her process is really working well. Out of 150,000 parts, 139,968 are defect-free. Based on the Six Sigma Theory, what sigma level is the process at? To get six sigma quality, how many defects can she tolerate out of 150,000 parts?

1. C-Spec, Inc. is attempting to determine whether an existing machine is capable of milling an engine part that has a key specification of 4 -+0.003 inch. After a trial run on this machine, C-Spec has determined that the machine has a sample mean of 4.001 inches with a standard deviation of 0.0012 inches.

a) Calculate the Cpk for this machine.

b) Should C-Spec use this machine to produce this part? Why?

change Sample 1, 985 reading to 976

25. Resistors for electronic circuits are manufactured on a high-speed automated machine. The machine is set up to produce a large Page 342 run of resistors of 1,000 ohms each. To set up the machine and to create a control chart to be used throughout the run, 15 samples were taken with four resistors in each sample. The complete list of samples and their measured values are as follows: SAMPLE NUMBER READINGS (IN OHMS) 1 1,010 991 985 986 2 995 996 1,009 994 3 990 1,003 1,015 1,008 4 1,015 1,020 1,009 998 5 1,013 1,019 1,005 993 6 994 1,001 994 1,005 7 989 992 982 1,020 8 1,001 986 996 996 9 1,006 989 1,005 1,007 10 992 1,007 1,006 979 11 996 1,006 997 989 12 1,019 996 991 1,011 13 981 991 989 1,003 14 999 993 988 984 15 1,013 1,002 1,005 992 Develop an X-chart and an R-chart and plot the values. From the charts, what comments can you make about the process? (Use three- sigma control limits, as in Exhibit 10.13.)