ALABAMA AIRLINES ON-TIME SCHEDULE
Alabama Airlines opened its door in December 2001 as a commuter service with its headquarters and only hub located in Birmingham. A product of airline deregulation. Alabama Air joined the growing number of short-haul, point-to-point airlines, including Lone Star, Comair, Atlantic Southeast and Skywest.
Alabama Air was started and managed by two former pilots, David Douglas (who had been now-defunct Midway Airlines) and Micheal Hanna (formerly with Continental). It acquired a fleet of 12 used prop-jet planes and the airport gates faceted by Delta Airlines in 2001 when it curtailed flights due to the terrorist attacks of 9-11.
One of Alabama Air’s top competitive priorities on is on-time arrivals. The airline defines “om-time” to mean any arrival that is within 20 minutes of scheduled time.
Mike Hanna decided to personally monitor Alabama Air’s performance. Each week for the past 30 weeks, Hanna checked a random sample of 100 flight arrivals for on-time performance. The table that follows contains the number of flights that did not meet Alabama Air’s definition on time:
SAMPLE (WEEK) | LATE FLIGHTS | SAMPLE (WEEK) | LATE FLIGHTS |
1 | 2 | 16 | 2 |
2 | 4 | 17 | 3 |
3 | 10 | 18 | 7 |
4 | 4 | 19 | 3 |
5 | 1 | 20 | 2 |
6 | 1 | 21 | 3 |
7 | 13 | 22 | 7 |
8 | 9 | 23 | 4 |
9 | 11 | 24 | 3 |
10 | 0 | 25 | 2 |
11 | 3 | 26 | 2 |
12 | 4 | 27 | 0 |
13 | 2 | 28 | 1 |
14 | 2 | 29 | 3 |
15 | 8 | 30 | 4 |
1- Using a 95% confidence level, plot the overall percentage of late flights (p) and the upper and lower control limits on a control chart.
2- Assume that the airline industry upper and lower control limits for flights that are not on-time are .1000 and .0400 respectively. Draw them on your control chart.
3- Plot the percentage of late flights in each sample. Do all samples fall within Alabama Airlines control limits? When one falls outside the control limits, what should be done?
4- What can Mike Hanna report about the quality of service?