A single server priority queue with server failures and queue flushing

We consider a singler server queue serving two classes of customers according to a preemptive resume head of the line priority discipline. The server is prone to failures and at the time that they occur, all customers are flushed out of the system. The system is analyzed under the assumption of a bulk arrival Poisson arrival process, exponential service times, general repair times and exponential interfailure time.