Finding the Right Number of Servers in Real-World Queuing Systems

Real-life queuing problems tend to be complex and ill-defined, and exact mathematical approaches are therefore illusory. This has to be taken into account when one wants to determine the right number of servers in a real-life queuing system, a problem of considerable practical importance. We suggest a number of approaches to find the number of servers. These approaches are both simple and flexible enough to cover a wide variety of queuing situations. Most of these approaches are based on the normal distribution, and their derivation is similar to the one used in one-period inventory models. Formulas based on classical queuing equations are also discussed.