Analysis of Teller Service Times in Retail Banks

Retail banks typically staff teller lines as if all tellers had the same service capabilities. Likewise, queuing models to recommend staffing levels often assume that all servers have the same service time distribution and that this distribution is exponential. These assumptions are motivated more by operational and analytical convenience than supported by data. Until recently there have been little available data to test these assumptions and their impact on customer service. This article presents results from analyzing a large dataset of teller service times from a retail bank. The validity of common teller staffing assumptions are explored along with the impact that deviations from the assumptions have on staffing recommendations obtained from queuing models.