Value of condition monitoring information for maintenance decision-making

This paper provides a methodology to assess the value of condition monitoring for the maintenance decision-making on a deteriorating single-unit system. A general deterioration/failure model is first proposed for a system subject to competing failure modes due to wear and traumatic “shock” events. Based on this model, the mathematical cost models for two maintenance policies (i.e. block replacement and periodic inspection replacement) are developed. Finally, the value of the condition monitoring information obtained through the inspections is investigated by comparing on numerical examples of the optimal expected costs of both proposed policies. This work shows how the analysis of the maintenance costs savings using the maintenance cost models developed in this work can be used to justify or not the choice to implement an inspection/replacement policy based on condition monitoring information and to invest in condition monitoring devices. It is indeed useful to follow closely the actual evolution of deterioration path to adapt the maintenance decisions to the true state of the system to improve the maintenance policy performance and decrease its costs.