Clarification of goals

First, check prerequisites

• What is the product used for?
• Who will use it?
• What environment is the product used in?

Comprehension difficulties

• Cannot understand unfamiliar terms or descriptions
• Cannot remember much information at a time
• It takes time to understand, accept, and remember information

Simple and easy to understand and use

Simple and easy for anyone to understand and operate

• How to use it is clear just by looking at it
• Easy common terms and expressions
• Appropriate number and position of operation buttons
• Easy, simple operation
• Clear-cut feedback displayed to show operational status
• Product able to be operated at the user's pace

Vision and hearing difficulties

• Cannot see or have difficulties in seeing information
• Have difficulty seeing small or low contrast displays
• Have difficulty focusing on nearby objects
• Height of vision for aged persons and wheelchair users is low
• Cannot hear
• Have difficulty hearing high or soft tones
• Have difficulty sensing danger in an emergency, such as a fire

Clear displays and easily recognized expressions

Displays and expressions should be universally recognizable by people looking at, hearing, or touching products

• Several options for expression of information should be available
• Functional areas should be arranged to be easily identifiable
• Arrange characters and figures to be easily readable (size and contrast)
• Adequate color scheme and number of colors.
  Check whether instructions rely on colors alone
• Appropriate information displayed
• Announcements and voice guidance easy to hear and follow

Usage/mobility difficulties

• Limited strength or limited grip
• Cannot undertake detailed work or immediate action
• Must use both hands
• Reach limited, cannot reach high or low
• Have difficulty doing continuous work in bent posture for long periods
• Limited balance or posture

Aim to create relaxed posture and reduced physical load

Product use should not involve physical discomfort

• Not too much strength needed to control the product
• Care for user in transport and installation
• Care for users when holding the product or maintaining their position using the product
• Minimum action to control the product.
  No immediate action necessary
• User can use the product with one hand, either left or right
• Product should be easy to use, regardless of the user's size
• The product should not force the user to maintain a certain posture under a load or the same posture for long periods
• Consider users in wheelchairs so they can use the product easily

Limited safety and convenience

• Cannot cope with incorrect operation
• Tend to forget to turn off
• Preparation, finishing, or maintenance is difficult

Pursuit of safety and convenience

The pursuit of safety and convenience is a major premise in development

Consideration of user feelings

Do not forget user feelings, such as happiness and joy, when obtaining and using products