Service Management: Operations, Strategy, Information Technology 8th Edition by James Fitzsimmons,Mona Fitzsimmons,Sanjeev Bordoloi

Exercise 15

In Example 6.2, the ambulance supervisor now has decided to double the response time sample size to 8 calls per day. Calculate the new UCL and LCL for a revised X -chart. For the next week, you record the following sample of daily mean response times: 5.2, 6.4, 6.2, 5.8, 5.7, 6.3, and 5.6. Would you be concerned?