Queueing analysis of a VoIP call center under retrial policy with re-service, server maintenance, and service disruptions

This paper develops a retrial queueing framework for a Voice over Internet Protocol (VoIP) call center server with two obligatory service phases. Incoming voice packets arrive according to the Poisson process. The model captures caller behavior involving potential re-service requests based on satisfaction after the first phase, introducing dynamic retrial effects. It integrates operational uncertainties such as service disruptions due to malware attacks and immediate repair processes. Additionally, server maintenance activities and post maintenance buffer searches are integrated to reflect realistic system operations. The supplementary variable technique is employed to derive steady state solutions for performance evaluation. Numerical analysis highlights the influence of key parameters on system performance. To enhance the study, cost optimization is performed using the Particle Swarm Optimization (PSO) technique, offering effective strategies to balance service quality and operational cost.

کلیدواژه ها:

retrial ، queue ، repair ، server ، re-service