ABSTRACT
As the last serving unit in each store, the checkout operation unit has a very important role in determining customers’ satisfaction level for the received services. The objective of this study was to analyze the quality of services in checkout operation units in Refah chain stores in Tehran Province using queuing theory. The required data were gathered through a questionnaire. The quality of the performance of Refah chain stores’ checkout operation units was evaluated and the overall system utilization was estimated at 73.97%. Weekdays, day time, and the location of the store are some factors that influence the efficiency of services.