TriCities Airlines flies several daily commuter flights to and from New York City, Washington, D.C., and Boston. The company has been flying a fixed daily schedule of flights, but it is now deciding...

TriCities Airlines flies several daily commuter flights to and from New York City, Washington, D.C., and Boston. The company has been flying a fixed daily schedule of flights, but it is now deciding whether to change this schedule. Each potential flight has an estimated net revenue based on the typical number of passengers for the flight. (See Figure 5.37 for a listing of all potential flights and their net revenues.) The company owns 4 airplanes, and it does not anticipate buying any more. There is a fixed cost of $1500 per plane per day that flies any flights. However, a plane that is not used does not incur this fixed cost. We assume (although this could be relaxed) that there is no required delay time on the ground; therefore, if a flight arrives in Boston at time 10, it can leave on a new flight at time 10. (We measure time in military time.) Also, any plane that arrives in a city after its last flight of the day has two options. It can sit overnight in that city, or, at a cost of $500, it can be flown empty to another city overnight. The company’s objective is to maximize its net profit per day, which equals net revenues from flights flown, minus fixed costs of flying planes, minus overnight costs of flying empty.

Objective To develop a network model for scheduling the airline’s flights, given its available aircraft, to maximize net profit from the flights.