A Note on Optimal Maintenance Policy and Sale Date of a Machine

In the paper “Optimal Maintenance Policy and Sale Date of a Machine,” Dr. G. L. Thompson [Thompson, G. L. 1968. Optimal maintenance policies and sale date of a machine. Management Sci.14(9, May) 543–550.] provided a model to interrelate economic life and maintenance policy, using Pontryagin's maximum principle. His results are very interesting, but these can be made more representative of the real life by a simple modification of the deterioration function d(t).