Gregs Airlines opened its doors in June 2014 as a commuter service, with its headquarters and only hub located in Birmingham. A product of airline deregulation, Gregs Air joined the growing number of successful short-haul, point-to-point airlines, including Lone Star, Comair, Atlantic Southeast, Skywest, and Business Express. Gregs Air was started and managed by a former pilot, Greg Szerbak (who had been with the defunct Eastern Airlines). It acquired a fleet of 12 used prop-jet planes and the airport gates vacated by Delta Air 2013 downsizing. With business growing quickly, Szerbak turned his attention to Gregs Airlines toll-free reservations system. Between midnight and 6:00am, only one telephone reservations agent had been on duty. The time between incoming calls during this period is distributed as shown in Table 1. Szerbak carefully observed and timed the agent and estimated that the time taken to process passenger inquiries is distributed as shown in Table 2.
Time Between Calls (Min) Probability
1 0.11
2 0.21
3 0.22
4 0.20
5 0.16
6 0.10
Table 1. Current Incoming Call Distribution
Time to Process Inquiries (Min) Probability
1 0.20
2 0.19
3 0.18
4 0.17
5 0.13
6 0.10
7 0.03
Table 2. Service Time Distribution
All customers calling Gregls Air go on hold and are served in the order of the calls unless the reservations agent is available for immediate service. Szerbak is deciding whether a second agent should be on duty to cope with customer demand. To maintain customer satisfaction, Gregs Air does not want a customer on hold for more than three minutes. What would you advise Gregs Air to do? Create a simulation model to investigate the scenario. If one agent is not enough, justify that hiring a second agent is sufficient.