Waiting Line

Line Study

The Psychology of Waiting Lines by Don Norman notes.

La Prima in Wean Hall, Carnegie Mellon University


Traffic Areas

Intersection between Waiting Line and Hallway
Front Door Area
(left to right) Observation notes. Customer waiting time track.
  • Five staffs work at La Prima at one time: an order delivery, a payment collector, two coffee makers, and a food storage organizer.
  • The crowded times are always in between classes.
  • During less peak hours, customers wait for 1–2 minutes for their coffee.
  • During peak times, customers wait for 4–6 minutes for their coffee.
  • The Cross section and front door traffics happen all the time. However customers seem like the traffics do not bother them. While waiting in lines, most customers look at their phone and know when to let others pass by. The customers and passers seem to know how the La Prima area works. The system works fine. However, the waiting line can definitely be improved.

Data Visualization

1st Iteration


2nd Iteration



(Left) Time frame limit. (right) Important points to present.

Graphic and video visualizing process