OPERATION MANAGEMENT
CASE B
SELF-SERVICE CANTEEN

1- What is the peak demand for the restaurant in terms of users per hour?

The opening hours of the canteen are from 11:30 am to 2:00 pm from Monday to Friday.

After interviewing the cashier, we learned that satisfied demand is approximately 400 to 500 people during those hours at a peak. This means that in an hour, the average number of customers is 180 people.

Moreover, we stood at the entrance for ten minutes observing how many people left without eating because of factors such as:
Too many people waiting in line
The menu of the day

We counted 16 people, which means that in an hour, there is an unsatisfied demand of 96 people. (11 out of 16 people leave because of the line and 5 because of the food).

In total, the peak demand reaches 276 people per hour.

2- What do you estimate as the peak capacity (for flow rather than seating)?

We observed that the slowest part of the procedure is the paying. There are three ways of paying: by credit card, with the student card or by cash.

The payment procedure lasts 1 minute when the customer is paying by credit card for a full meal (main dish, dessert and beverage). So, in an hour this totals up to 60 customers per hour.

When paying by cash, it takes the cashier about 45 seconds to complete one payment, that is, 80 people per hour.

Finally, when using a student card, the payment procedure lasts approximately 40 seconds, which is equal to 90 people per hour.

In conclusion, in an hour, the peak capacity reaches 230 people. The peak demand, including the satisfied demand and the unsatisfied demand related to the long line, is equal to 246 (180 + 11*6) people, so the peak capacity is insufficient to cover the peak demand.

3- What limits the flow through the restaurant?

At a peak, the whole payment procedure including the line up to the counter and the actual payment lasts 8 minutes (this time is a bit less when paying by