Performability evaluation and optimization analysis of repairmen for large-scale networks

Today, many large usages of computer systems, cloud computing, high-performance networks and their connections through networks are available electronically and they rapidly increased. These large-scale networks are fault tolerant and require a repairmen policy for maximising Quality of Service (QoS). However, obtaining QoS of large-scale networks analytically is difficult due to the state space explosion problem. In this paper, a simple and flexible approximate analytical modelling approach is presented in order to overcome state space explosion problem of large Markov models. The mean queue length results obtained from the proposed model and Spectral expansion solution are in good agreement. It is shown that this approach can handle large state spaces. An optimisation study is also presented together with the relationship of the number of servers and number of repairmen.