A novel approach for optimal replacement threshold and inspection scheme for condition based maintenance
Journal of Quality in Maintenance Engineering
ISSN: 1355-2511
Article publication date: 8 December 2020
Issue publication date: 28 March 2022
Abstract
Purpose
The purpose of this paper is the simultaneous determination of optimal replacement threshold and inspection scheme for a system within condition-based maintenance (CBM) framework.
Design/methodology/approach
A proportional hazards model (PHM) is used for risk of failure and a Markovian process to model the system covariates. Total expected long-run cost (including replacement, inspection and downtime costs) is formulated in terms of replacement threshold and inspection scheme. Through an iterative procedure, for all different values of replacement thresholds, their associated optimal inspection scheme is determined using an effective search algorithm. By evaluating the corresponding costs, the optimal replacement threshold and its associated optimal inspection scheme are, then, identified.
Findings
The mathematical formulation, that takes into account all different costs, required for the simultaneous determination of optimal replacement threshold and optimal inspection scheme for an item subjected to CBM using PHM is provided. The proposed approach is compared against classical age policy and one state-of-the-art policy through a numerical example. The results show that the proposed approach outperforms other comparing policies.
Practical implications
In practical situations where CBM is implemented, inspections and downtime often incur cost. Under such circumstances, findings of this paper can be utilized for the determination of optimal replacement threshold and optimal inspection scheme so that the CBM cost is minimized.
Originality/value
In most of the reported researches, it is often assumed that inspections have no cost and/or that the time for replacements (either preventive or at failure) is negligible. In the contrary, in this paper the author takes all cost factors including inspection costs, replacement time(s) and their associated downtime costs into account in the simultaneous determination of optimal replacement threshold and optimal inspection scheme.
Keywords
Acknowledgements
The author wishes to thank the referees and the associate editor for their helpful comments concerning this paper.
Citation
Golmakani, H.R. (2022), "A novel approach for optimal replacement threshold and inspection scheme for condition based maintenance", Journal of Quality in Maintenance Engineering, Vol. 28 No. 2, pp. 277-295. https://doi.org/10.1108/JQME-05-2020-0036
Publisher
:Emerald Publishing Limited
Copyright © 2020, Emerald Publishing Limited