Improving service for service systems with different arriving rate

We investigate the performance of service systems such as telephone call centers or Internet access points. Previously, birth-death models were developed to compare the throughput of a system that informs customers about anticipated delays and a one that does not give state information as customer arrive. The results were obtained based on the assumption that the two systems have the same parameters (arrival rate, service rate, mean reneging time, mean waiting-time threshold). In reality, it is more likely that they have different arrival rates. We prove results on system throughput with the condition that the parameters of the two systems have the same ratio. We also give sufficient conditions for a system to have a higher throughput. Comparisons for throughput, server utilization and mean response time are also done by simulation. We present the results from the simulation and a brief conclusion is given.