Referring to Problem 18-12, assume the Ajax managers determine any issues identified by the control charts were caused by one time events. The data for weeks 41 through 45 are in the Ajax-Extra file.
a. Using the control limits developed from the first 40 weeks, do these data indicate that the process is now out of control? Explain.
b. If a change has occurred, brainstorm some of the possible reasons.
c. What will be the impact on the control charts when the new data are included?
d. Use the data in the files Ajax and Ajax-Extra to develop the new control charts.
e. Are any of the typical control chart signals present? Discuss.