On Two-Server Poisson Queues with Two Types of Customers

Abstract
This paper considers two schemes for a steady-state queue with two types of customers served by two desks, the customers arriving mixed in a Poisson stream and having negative-exponential service-time distributions, with different means characterizing the two types of customers. In Scheme I each type has a particular desk, for which he queues on arrival. In Scheme II all customers keep in a single queue and proceed indifferently to either desk. Numerical remits indicate that Scheme II reduces mean queue size and queuing times, generally with advantage to both types of customers.