An effective age-based preventive replacement model

摘要

The paper introduces a new model to find the optimal timing of preventive replacement of an equipment. The traditional models do not take the down times into account when inspections and repairs are being performed. The distribution of time to failure really depends on the effective age of equipment, which can be computed by solving a monotonic equation including the repair and inspection down times. A mathematical model is then developed based on the modified probabilistic features where the chronological age is replaced by the effective age. The expected cost per unit time is first minimized, and then a mulitobjective approach is introduced. The models and their solutions are illustrated with numerical examples.