| Article ID: | iaor2009152 |
| Country: | Netherlands |
| Volume: | 179 |
| Issue: | 1 |
| Start Page Number: | 275 |
| End Page Number: | 276 |
| Publication Date: | May 2007 |
| Journal: | European Journal of Operational Research |
| Authors: | Zhang Yuan Lin |
In this short paper, a bivariate optimal replacement policy for a repairable system with a geometric process maintenance model is discussed. Zhang and Sheu obtained different expression of the long-run average cost per unit time (i.e. average cost rate) of the system respectively. We show that both of their results are correct, therefore, Sheu's comment on the result of Zhang is wrong.