1 A statistical process control monitoring system samples
the inside diameter of ball bearing every hour. Measurements
were taken every hour for 25 hours. The target thickness,
T, is the average.
0.992
1.015
0.988
0.996
1.015
1.000
0.989
0.994
1.018
0.997
1.020
1.007
1.006
0.982
1.001
0.992
1.020
0.993
0.978
0.984
0.990
1.015
0.983
1.011
0.987
What is the population standard deviation, ??
b) What are the Upper and Lower Action Line?
c) What are the Upper and Lower Warning Line?
d) Using 3, what are the Upper and Lower Control limits?
e) Plot the Target Thickness and parts b) – d) in a chart using
R.
f) Is this data in a process of control? How do you
know? Explain your answer. If it is not, what are some
recommendations you can give to get the data back into a process of
control.
h) Redo, the previous example using a CUSUM chart. Is the
conclusion the same? If it is not in a process of control,
what are some recommendations you can give to get the data back
into a process of control.