Repair limit replacement

Hastings introduced the concept of repair limits for replacement problems, the basic idea being that if, at a given time, the repair of a vehicle, for example, is sufficiently expensive, then it will be economical to replace the vehicle with a new one. Numerical results also demonstrate that repair limits decreased with age. In addition, it was assumed that, at a certain age, vehicles should be replaced whatever the repair cost. This paper addresses theoretical issues surrounding these questions.