Allison Jon, the manager of an 800-number reservation service for a nationwide chain of luxury hotels, is concerned about the productivity of her operation. Analysis of past data shows that it should take an average of four minutes to properly process a reservation. To setup a control chart for reservation service time, Allison records the time it takes to complete the reservation. She randomly samples 5 reservations every day for 30 days.

Set up the appropriate control charts for these 30 days of data. Data File in BbLearn. Plot the data for these 30 days in an xbar chart and an r chart.

Now monitor the process. Ten days of data have been collected since creating the control charts.

A second 10 days of data have been collected.

Questions:

1) Are you comfortable with the control limits set? Explain.

2) Comment on the reservation process in the first 10 days of monitoring. If the control chart indicates out-of-control, be specific - which days, the pattern, and whether it is the xbar or r chart.

3) Comment on the reservation process in the second 10 days of monitoring. If the control chart indicates out-of-control, be specific - which days, the pattern, and whether it is the xbar or r chart.

4) If the monitoring results show that the average reservation time or range in reservation time requires investigation, suggest some potential causes to be investigated.

Be specific and be sure to explain how the potential causes relate to the point or patter on the control chart that requires investigation.