An M[x]/G/1 system with startup server and J additional options for service

We consider an M-[x]/G/1 queueing system with a startup time, where all arriving customers demand first the essential service and some of them may further demand one of other optional services: Type 1, Type 2,..., and Type J service. The service times of the essential service and of the Type i (i = 1, 2,..., J) service are assumed to be random variables with arbitrary distributions. The server is turned off each time when the system is empty. As soon as a customer or a batch of customers arrives, the server immediately performs a startup which is needed before starting each busy period. We derive the steady-state results, including system size distribution at a random epoch and at a departure epoch, the distributions of idle and busy periods, and waiting time distribution in the queue. Some special cases are also presented. (c) 2007 Elsevier Inc. All rights reserved.