Diffusion Approximation for an M/G/m Queue

This paper deals with the M/G/m queueing system in the steady-state. Applying the method of diffusion approximation, we provide approximate formulas for the distributions of the number of customers, the waiting time and the busy period. We also discuss the relation between the heavy traffic approximation and these approximations. In order to examine the accuracy of the approximate formulas, they are numerically tested on some examples.