Analysis of the SelfCheckout System

1
Analysis of the Self-Checkout System

• Vaida Kazakeviciute
• Aarthy Subramanian

2
Introduction to the System

• What is a self checkout system
• Grocery cart
• Scanner
• Bagging area
• Touch screen display
• Credit/debit card scanner
• Receipts area
• Cash and coupon scanner

3
Introduction Contd

• Advantages of the System
• Where the self checkout system is used
• Users of the system
• Systems studied (Giant and Stop Shop)

4
Overview of the Results

• Strengths found
• Easy to use
• Faster Checkout
• Privacy about items bought
• Weaknesses found
• Lesser user control
• Error recovery
• System state

5
Ethnographic Observation

• Results
• The system is used more during the peak hours and
  weekends
• People use system more when number of items if
  less
• People prefer the traditional human-assisted
  checkout over the self checkout system if both
  are available
• Older people have more problems

6
Ethnographic Observation

• Design Implications
• The main issue scanning the items
• Products lack consistency and location of
  barcodes in packaging

7
Survey

• Results
• 90 of people used in the survey have used the
  system at least once
• People used the system to speed up the checking
  out process
• Design Implications
• Main issue weighting the items withour barcode
• Need to recreate the system so it is more user
  friendly

8
Usability Testing

• Results
• People take less time to checkout if they use a
  credit/debit card instead of cash
• Most people did not need any human assistance
• Design Implications
• Add a Back button
• Need clear instructions on how to look up items
  code
• Error handling

9
Heuristic Evaluation

• Results
• Most problem found were in the user control and
  freedom area
• Process of weighting items not clear
• Design Implications
• Add Undo/Redo options or Back/Forward
• Add Home button
• Instructions on weighting items without barcode

10
Cognitive Walkthrough

• Results
• Users between ages 18 and 50 would be able to
  perform most of the tasks
• System provided good feedback for user actions
• Design Implications
• Usability issue in screens that dont provide
  backward navigation
• Senior citizens might find some tasks confusing

11
Observations

• Overall Usability is good
• Shoppers use system only when number of items is
  small
• Possible problem areas checking out barcode,
  coupon entry screen
• Most useful technique survey
• Less useful technique cognitive walkthrough

12
Design Recommendations

• Back and Main Menu buttons on screens
• Clear instructions for checking out items without
  barcode
• Better error recovery