Title: Design of a periodic inspection policy in heterogeneous systems with two types of components
Authors: Maria Lucia Bautista Barcena - Universidad de Extremadura (Spain) [presenting]
Inmaculada Torres Castro - Universidad de Extremadura (Spain)
Abstract: A heterogeneous system consisting of monitored and non monitored components is analyzed. Monitored components are subject to a degradation process (following a gamma process) and they fail when their degradation level exceeds a corrective threshold. Condition-based maintenance is applied to reduce the impact of the failures on them. Non monitored components are subject to sudden failures. They can only be maintained correctively upon failure. Maintenance team takes a while to repair the system. The system is inspected periodically every $T$ time units. In these inspection times, if the degradation level of a monitored component reaches a certain preventive threshold, this component is replaced by a completely new one. Also, an opportunistic maintenance policy is implemented to take advantage of system failures and perform preventive maintenance on some components if necessary. Each maintenance task implies a certain cost and each monitored component is assumed to provide a reward which decreases when the deterioration level of the component increases. Assuming infinite time span, the expected cost rate of the system is minimised through the optimization of the preventive thresholds and time between inspections. Meta-heuristic algorithms such as genetic algorithms or pattern search, combined with typical Monte Carlo simulation methods, are used to compute the maintenance cost of the system.