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ThesisItem Open Access Stochastic alternating renewal processes models for reliability analysis of multi-component systems incorporating queuing delay(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-10) Agarwal, Shweta; Singh, S.B.In the real-world scenario, most of the systems are comprised of more than one component and hence it becomes inevitable to estimate the reliability and availability of multi-component systems. Also, in most of the complex repair models the system fluctuates between up-state and down-state and the failure is revealed at the time of inspection. Keeping the aforementioned facts in view, the present research is centered to propose the reliability and availability models on the basis of derived proposition, Markov process, renewal theory. In this study, six models are introduced. Model [1] aims to propose a notion of alternating renewal process to mathematically model a multi-failure complex system to develop its availability and maintenance measures. In the study, M/E2/1 queueing model with infinite waiting space during service times of components has been worked out under FCFS discipline. The primary objective of the paper is about obtaining the system’s reliability, availability, and the optimal interval period with minimum maintenance cost. Model [2] analyzes the reliability characteristics of batch service queuing system with a single server model which envisages Poisson input process and exponential service times under First Come First Served (FCFS) queue discipline. With the help of renewal theory and stochastic processes the model has been designed to discuss the reliability and its characteristics. Model [3] considers the reliability characteristics of a multi-component system envisaged with Poisson arrivals and analyzed service in bulk. In the general bulk service rule the repair process is initialized when a threshold of “a” number of failed components is reached with the maximum capacity “b”. Considering the above facts reliability and availability expressions of the considered model has been derived. Model [4] treats a risk system in which at the occurrence of failure due to any of the mode of failures the failed component joins a M/G/1 queue. After the completion of the repair, whenever the serviceman becomes idle it starts an exponential classical vacation in which the serviceman does not serve the failed unit. Incorporating the above cited facts, expressions for estimating the reliability and its other measures are derived. Model [5] investigates the reliability and other measures related to it for a periodically inspected system. Whenever any of the components gets failed it joins the M/G/1 queue with a waiting threshold. While if the service of the failed components is commenced in the threshold amount of time, then it remains to its completion. Various reliability measures like availability, maintenance, long run maintenance cost rate have been estimated for the considered system. Model [6] analyses a periodically inspected system subject to imperfect maintenance policy. The considered system is inspected and maintained periodically and passes through a fixed number of imperfect repairs before being replaced. Incorporating the given facts, the reliability of the periodically inspected system is evaluated
