Modified block replacement with used items at scheduled periods and at failures

In maintenance engineering, it is intended that in a Block Replacement Policy (BRP) model, items are removed and replaced by new ones at failure and at the beginning of each scheduled time kT (fe = 1, 2, ...). It was proved that this kind of strategies has its limits and didn't cover others particular situations. This paper addresses a modified BRP model, that in the same conditions, instead of using new items, used items are provided. The idea behind this model is to minimize the expected total cost while to reduce the impact of the removed items on the environment.