Performance assessment of a network system composed of three subsystems using a multi-repair tactic

Abstract:This study investigates the reliability performance of a complex repairable system composed of three interconnected subsystems arranged in a series configuration. Subsystem-1 comprises clients working under the k/n: G operational scheme. Subsystem 2 has two identical Internet service providers (ISP1 & ISP2) of uniform capacity in parallel configuration such that at least one ISP is required for the performance requirement of connectivity, while Subsystem 3 is a central server unit. At least k clients are required for successful operation of the subsystem, and one ISP and a server can fill the operation requirement. Together with multiple failures of the subsystems, two types of repairs were employed for repairing the units of the subsystems. General repair is used for minor degraded failed states, while we employ a joint probability distribution Gumbel-Hougaard copula to restore the completely shut-down system. The novel method, the supplementary variable method and the Laplace transform application are incorporated into the analytical study of the system performance. Researchers examined the traditional reliability measures for the entire system. An analytical study predicts the future behaviour of the stem in the long run. The results, discussion and conclusion for specific values of parameters highlight the best and worst performance of the system. Keywords: Multi-state system; Internet Service Providers (ISP) network; series configuration; k/n: G configuration; general repair and copula repair; MTSF; profit analysis.