
176 Six Sigma Case Studies with Minitab
®
time, with three factors: patient arrival time (morning and afternoon), regis-
tration desks (1 and 2), and procedure (acne, scars, and laser surgery).
Figure10.25 partially shows the waiting times of the patients as entered in
the Minitab
®
worksheet. Open the CHAPTER_10_2.MTW worksheet for the
complete set of data (the worksheet is available at the publisher’s website; the
data from the worksheet are also provided in the Appendix).
Click on “Multi-Vari Chart” as was shown in Figure10.2. As a result, the
dialog box shown in Figure 10.26 opens. Using the “Select” button, select
“Waiting Time” for “Response” ...