This paper examines the reliability of a k-out-of-n system, where a single server takes several vacations. In addition to servicing defective system components, the server offers its services to external customers. Poisson distribution is used to describe the arrival of externally failing customers and the failure rate of internal components. The service time of internal components and external customers follows an exponential distribution. N policy governs the non-preemptive external services. When the number of defective system components exceeds N, the server’s vacation will end and internal service will resume. The Matrix Geometric method is used to analyse the model. A suitable cost function and several system performance measures are established.