Analysis and performance evaluation of a bulk arrival retrial queue with impatient customers, server breakdowns, and bernoulli vacation policy
摘要
This paper analyzes a single-server retrial queue with batch arrivals, event-driven impatience, and active server breakdowns, incorporating reservation time and a Bernoulli vacation policy. Arriving batches finding the server unavailable collectively enter the retrial orbit or leave the system. The server may fail during service, requiring immediate repair; upon failure, customers may remain or move to a service orbit, inducing a reservation period. This model has practical applications in domains such as computer networks and cloud computing. Using the supplementary variable method, we derive steady-state probability distributions, stability conditions, and key performance measures of the system, including the average number of customers in the orbit and system, and the expected busy and idle periods of the server. Furthermore, we analyze the system’s reliability and formulate the cost function of our model. A numerical analysis is conducted, including sensitivity study, cost function optimization with both L-BFGS-B algorithm and Particle Swarm Optimization (PSO), where both methods reach the same numerical optimum within the adopted stopping tolerances. Additionally, three one-input Adaptive Neuro-Fuzzy Inference System (ANFIS) surrogate models are developed for the mean orbit size over selected stable ranges. The ANFIS outputs closely match the corresponding analytical curves for