In response to customer specific time guarantee requirements, service providers can offer differentiated services. However, conventional customer differentiation methods often lead to high holding costs and may have some practical drawbacks. We compare two customer differentiation policies:...

In this article we give a new derivation for the waiting time distributions in an M/M/c queue with multiple priorities and a common service rate by using elementary lattice paths counting. An advantage of the approach is that it does not require inversion of the Laplace-Stieltjes transform