This study considers a system of multi-server queues with two classes of impatient customers: high-priority and low-priority. Customers join the system according to a Poisson process and customers may abandon service after entering the queue for an exponentially distributed duration with distinct rates. In this paper. we consider last come-first served (LCFS) and first come-first serv... https://storeanimalwiz.shop/product-category/dog/