This article is © Emerald Group Publishing and permission has been granted for this version to appear here http://pfcservicesinc.com/). Emerald does not grant permission for this article to be further copied/distributed or hosted elsewhere without the express permission from Emerald Group Publishing Limited. DOI: http://dx.doi.org/10.1108/JQME-09-2014-0050 A Markov Decision Process Model Case for Optimal Maintenance of Serially Dependent Power System Components Daniel Bumblauskas, Ph.D. Department of Management, University of Northern Iowa, Cedar Falls, Iowa, USA daniel.bumblauskas@uni.edu; +1-319-273-6793 Citation for this article: Bumblauskas, D. (2015). “A Markov Decision Process Model Case for Optimal Maintenance of Serially Dependent Power System Components.” Journal of Quality in Maintenance Engineering. 21 (3), pp. 271-293. Available: http://www.emeraldinsight.com/doi/abs/10.1108/JQME-09-2014-0050. Emerald Literati Network Award for Excellence 2016: http://www.emeraldgrouppublishing.com/authors/literati/awards.htm?year=2016 This article is © Emerald Group Publishing and permission has been granted for this version to appear here (http://pfcservicesinc.com/). Emerald does not grant permission for this article to be further copied/distributed or hosted elsewhere without the express permission from Emerald Group Publishing Limited. DOI: http://dx.doi.org/10.1108/JQME-09-2014-0050 Purpose This paper is a case study for electrical power equipment to investigate the importance of dependence between series-connected system components in maintenance decisions. Design/methodology/approach A continuous-time Markov decision model is formulated to find a minimum cost maintenance policy for a circuit breaker as an independent component while considering a downstream transformer as a dependent component. Maintenance of the dependent component is included implicitly in terms of the costs associated with certain state-action pairs. For policy and cost comparisons, a separate model is also formulated that considers only the circuit breaker as the independent component. After uniformizing the continuous-time models to discrete time, standard methods are used to solve for the average-cost-optimal policies of each model. Findings The optimal maintenance policy and its cost differ significantly depending on whether or not the dependent component is considered.