A New Two-Dimensional Condition-Based Maintenance Model by Using Copulas

This paper introduces a new two-dimensional condition-based maintenance model for complex and repairable machining systems like computer numerical control machining tools. A joint distribution of condition and reliability indicators is constructed by using copula. The maintenance threshold is set on the cumulative hazard rate conditioning on intensity of work. A numeric example with assumed settings is provide to demonstrate the relationship between the maintenance threshold and expected cost rate. This is the first model jointly considering condition and reliability indicators in maintenance area; and being benefited by the features of copula, this model can be easily extended to model dependences among multiple indicators in practice.