Age-Based Replacement Policy With Consideration of Production Wait Time

In this paper, we consider the replacement of a unit that is subject to a dominant failure mode. The unit is usually replaced by an age-based replacement policy, either when a preset age limit has been reached, or when failure occurs before this limit. However, the unit can also be replaced when it encounters a random production wait and its age has reached a certain threshold. Using such an opportunity for replacement can help to minimize system downtime. We formulate this joint age-based replacement limit and threshold optimization problem with the objective of minimizing the expected cost per unit time in the long run. A real-data example is presented to illustrate the applicability and effectiveness of our model.