SERVER UNAVAILABILITY REDUCES MEAN WAITING TIME IN SOME BATCH SERVICEQUEUING-SYSTEMS

This article shows that in some queuing systems server unavailability is sometimes beneficial both to the system owner and to the customers. To be more specific, mean queue size and mean waiting time may decrea se even in the presence of server vacations. To this end, we first der ive the probability generating function of the batch service M/G(B)/1 system with multiple vacations. We, then, consider the case of exponen tial service and vacation times and show that under some parameter com binations, mean queue size decreases even in the presence of server va cations. We discuss the implications of this phenomenon. (C) 1997 Else vier Science Ltd.