This study investigates an apparel business model and the variables that underlie it. To do so, the study draws a general picture of the challenges of the industry nowadays and how the textile industry has been moving from a product based business to a service based one. Under this scope the crucial aspects of a service operating system are analyzed through three data bases; a clerk’s survey, a customer’s survey and the POS system information. The integration of these data bases allows to capture several variables of the system to study the clerk’s influence on the purchase and the purchase event itself: in which cases a customer purchases a good and in which the customer merely visits the store and leaves. Tasks such as the research of the behavior of these multi-variable scenarios can be managed through the application of business intelligence. This study adopted decision tree analysis to discover interesting rules that are coherent with the general picture of the industry and the current trends. Indeed, the rules reach to a clear conclusion; the clerks in the apparel retail stores are critical. The help they provide, and their responsiveness towards the customers’ behavior can definitely change the performance of the store.