Consider additional requirements and technology to further complicate your analysis of an Automated Teller Machine (ATM) design:

a) Use eye-tracker data to further analyze the product
b) Consider accessibility (universal usability) issues such as lighting, physical placement of ATM, etc.
c) Consider user profile issues, e.g. is this the first time a user is using an ATM?
d) Requirement to perform beta and/or market tests?
e) Are there other stress factors such as a looming time deadline or a personal safety issue?

a) Adding technology to usability test the ATM might prove insightful. Usability lab testing with speak-aloud enunciation of actions, recording of eye-tracking data, key press logging, video recording, etc. might prove to generate a large amount of data yet might yield trends in user roadblocks, and acceptance
b) Formal accessibility methods should be fully deployed for the simple reason to attract customers to the bank with limited abilities. Some, e.g. hearing impaired, might even prefer an ATM’s visual interaction design rather than the noise and distraction of the human (bank teller) interaction in a large, noisy banking center. ATM’s physical position might need to be lower to accommodate those of shorter stature or in a wheelchair.
c) If the design is clear, special help or guidance for the first-time ATM user might not be a key design consideration. Most users are knowledgeable, frequent, intermittent users. However, in the spirit of customer service, the use of the ATM should be clear and fluid for the novice user as well.
d) One might assume a bank would test market a new ATM design. After usability testing in a lab environment, surveillance could be performed at a particular bank to see how the users react (if at all) to the new design. Surveillance is already being performed as a physical security issue, and existing equipment might be useful to “watch” the ATM users in action.
e) Physical security has to always be a concern. Well-lit ATM stations, with clear notification of recording as a security measure, with mirror for those to see if someone is lurking behind, etc. are all considerations. A “cancel” button which would return the card for quick exit is already in place and users need to know of its existence.
Ask students if this is indeed a complete list, or are there other technologies that would further complicate the design. One example might be ATM interaction with a Smartphone. Another might be to for ATM interaction with e-payment systems such as Apple Pay or PayPal.