Customer expectations on average wait time in a physicians office are such that a wait of 10 minutes is understandable and expected while a wait beyond 30 minutes becomes intolerable. Increasing the number of magazines to read in your waiting area has not changed the customers perceptions 30 minutes or more is way too long. You observe the following wait times on a sample of 30 customers: 12, 34, 10, 22, 5, 16, 18, 43, 25, 14, 21, 19, 16, 14, 24, 12, 11 14, 18, 23, 34, 40, 17, 5, 13, 12, 23, 25, 32, 28.

1. What is the average waiting time and the variance (standard deviation) of the waiting time? What do you think are some reasons for this variability?
2. What is the process capability? (Cp=(USL-LSL)/6*, Cpk= Min [(USL-Mean)/3*, (Mean LSL)/3*]
3. Which measure is more appropriate here: Cp or Cpk? Why?
4. Suggest the upper and lower control limits of a control chart that would monitor the wait time?
5. What would you do (that is, what are some normal managerial actions) when you observe an out of control condition? Please be specific here with respect to the observed scenario.
6. Are control charts useful for this specific situation? Why or why not?
7. What are some ways by which you will alleviate the pain of the waiting customer?
8. What are some ways by which you will reduce the variance of the process?