Modeling the Management of a Queue at a Bank


This model assumes that the number of tellers at a bank is managed based on the current size of the queue. Following is a summary of the assumptions made for this model:

1) Customers arrive at the bank about once per minute.
2) It takes, on average, two minutes to service a customer.
3) The number of tellers is adjusted once every five minutes.
4) There is a targeted range for the acceptable queue size.
5) If the queue length is greater than (but less than twice) the upper target and there is a teller available, a teller is added. If the queue length is greater than twice the upper target, two tellers are added.
6) If the queue length is less than the lower target and there are two or more tellers (note, at least one teller must always be available), a teller is removed.


Making Better Decisions In An Uncertain World