Problem
A sandwich stand in a popular food court is looking to provide sufficient staffing to meet customer demand. When customers arrive at the stand, they can complete a menu form to customize their order. They submit the form to the clerk, who processes their order, and collects payment. The arrival rate is 24 customers per hour. The service rate is 13 per hour. There is a lot of choices at the food court so customers will easily choose a different food option if they feel that they did not receive quick and superior customer service. The owners estimate that the cost of customer waiting is estimated at $26/hour per customer waiting and the cost of each counter server is $19 per hour, what is the optimal number of servers that should be working during the peak time?