The Problem Benny's Burgers is fast food restaurant located in a small to mid-sized town in the Intermountain West. Benny's Burgers has been in existence for several years and the owner, Mr. Benny Bengal, is wondering if upgrades are needed to remain competitive. Mr. Bengal has observed that there are times of peak business where the line grows very long at the drive-through. During these periods he has observed people slowing to pull into the drive-through and then deciding not to because of the line. He has asked us to model his system and make suggestions. Benny's Burgers consists of some basic steps that we need to model. First is the customer arrival rate. We need to model for the maximum traffic, so the owner of Benny's Burgers has provided us with the computer logs for Saturdays during the summer (the highest traffic day during the highest traffic time period). As customers approach, they are guided by curbing into a line. Once in the line, the first station is a combination menu display and speaker/microphone system through which the customer places their order. Once the customer has placed their order, they proceed to a payment window at which their payment for their order is collected and they receive their order. Once the customer receives their order, they exit the drive-through. Management is concerned about the ability of their current drive-through to handle the ever-increasing load and asked us to model the current system and makes suggestions. The drive-through itself is highly automated and the information system maintains logs on all aspects of operations. From these logs management has determined that customers are arriving about every 45 seconds to 3 minutes (45 to 180 seconds). They appear to spend between 30 and 90 seconds in the Order Placement process, and between 1 to 2 minutes (60 to 120 seconds) in the Payment and Order Receipt process. To management this seems entirely reasonable. If customers arrive every 90 seconds, they can pull directly up to the menu display and place their order and on to payment and order receipt window. If the payment process only takes 30 to 60 seconds, there should be no delay. Then the customer pulls forward and it takes another 60 seconds to process their payment and deliver their food. Why are there delays?