A Drive through window operations are becoming an increasing source of competitive advantage for the fast food restaurant business. McBerger’s has performed poorly in this area compared to Mandy’s, the leader in drive through operations. The service from a drive through window is staged. At the first stage, the customer places an order. At the second stage, the customer makes a payment at the payment window. Finally, at the third stage, the customer picks up the order. The time between consecutive customer arrivals is exponentially distributed with an average of 45 seconds. Currently, McBerger’s total service time (across three stages) averaged 55 seconds with a standard deviation of 35 seconds. Several new process changes were made. Assume that no customers abandon the system or are blocked after entry in either system ( before or after the change).
a. Competitors have experimented with a separate kitchen to service the drive through orders. When McBerger’s implemented this new “ plant within a plant” strategy, average service time remained at 55 seconds but with a standard deviation of 25 seconds. As a result of this change, did the average waiting time in queue increase, decrease, or remain the same?
b. McBerger’s began testing the installation of a transponder on a customer’s windshield that allowed the restaurant to scan the identification of the car. Using this technology, the customers were billed directly instead of paying at the window. As a result of this technology, do you think the average waiting time increased, decreased, or remained the same?