Two-Class Priority Queueing System with Restricted Number of Priority Customers and Catastrophes

In this paper, we analyze a two-class single-server preemptive priority queueing system with restricted number of
priority customers and catastrophes. The arrivals per class follow the Poisson process with exponentially distributed service times.
Customers are served on a first-come, first-served basis within their queue. Explicit expressions for the mean queue length and the
joint distribution are derived in the steady-state case for the number of high and low priority customers in the system. The analysis
is based on the generating function technique. Also, we study the impact of catastrophe on the system and other performance
measures.