Vehicle fleet planning. The Millersburg Supply Company uses a large fleet of vehicles which it leases from manufacturers. The company has forecasted the following pattern of vehicle requirements for the next 6 months:
Month
Jan.
Feb.
Mar.
Apr.
May
June
Vehicles required
430
410
440
390
425
450
Millersburg can lease vehicles from several manufacturers at various costs and for various lengths of time. Three of the parts appear to be the best available: a 3-month lease for $1700; a 4-month lease for $2200; and a 5-month lease for $2600. The company can undertake a lease beginning in any month. On January 1, the company has 200 cars on lease, all of which go off lease at the end of February. Formulate the problem of determining the most economical leasing policy as a minimum cost flow problem.