• Safety: Reducing the risk of injury and death
• Performance: Increasing productivity, quality, and efficiency
• Satisfaction: Increasing acceptance, comfort, and well-being

Iterative on three major phases: understand users, create a prototype, and evaluate the prototype.

This has to be done from the early stage of the design. Because even when designers attempt to consider human factors, they often complete the product design first and only then hand off the blueprint or prototype to a human factors expert to evaluate.

The goal of task analysis is to understand:

• Why - users’ goals and motivations
• What - the tasks and subtasks to achieve these goals (Workload, mental & physical demands, multitasking, human error.)
• When - the ordering and timing of these tasks (functions performed by human or by machines)
• Where - and the location and situation (Environment and context, eg. cold outdoors, wheelchair accessible, potential hazards)

Task analysis is a broad term that encompasses many other techniques such as use cases, user stories, personae and scenarios.

Personae are helpful for building the right scope of design target. One the one hand it prevents the natural tendency of the design team to assume users are like themselves (scope too narrow). One the other hand it is also helpful for avoiding an “elastic user” whose characteristics shift as various features are developed. Designing for an elastic user may create a product that fails to satisfy any real user. (scope too broad)

Scenarios (user journeys) also help define what's most important for user. When creating a scenario, tasks are examined, and only those that directly serve users’ goals are retained. Two types of scenarios are most important — daily use scenarios and necessary use scenarios. eg. Entering the car, entering the car during a snowstorm.

Personae and scenarios analysis is an early stage version of task analysis. It gives us confidence that the conceptual design can meet target users' needs before going into detail.

Use cases analysis is more detailed. It can be described in a more formal way in a flow diagram, helping move from conceptual design to a software or hardware prototype.

Standord wallet exercise This exercise provides a brief exposure to design thinking. The goal is to practice designing and recognizing a user’s need and then translating that need into a prototype product that is then evaluated

Change what operators do than change the devices they use. A workstation for an assembly line worker might be redesigned to eliminate manual lifting. Or a robot might be designed to lift the component.

Change the physical equipment that people work with. Apple’s design of the iPhone hardware and software demonstrates how important a focus on equipment design can be to a product’s success.

Changes the physical environment where the tasks are carried out. This can include improved lighting, temperature control, and reduced noise.

Designs of task, equipment and environment are usually considered together as the picture below. Cognition consideration are where we derives theories, principles and guidelines. Commonly seen cognition considerations are: Response Time & Delay

Enhances the knowledge and skills of people. This includes teaching and practicing the physical or mental skills. Training is most applicable when there are many repetitions of a task or long involvement with the job. Periodic training is also important for those tasks that are rare, but where performance is critical, such as fire drills and emergency first aid.

Changes the makeup of the team or organization by picking people that are best suited to the job

Changes how groups of people communicate and relate to each other, and provides a broad view that includes the organizational climate where the work is performed.

Heuristic Evaluation is done internally, with 3 individuals inspect the design and identify if there is anything violating design principles, safety requirement, etc.

10 Design principles:

• Create useful innovation: Address a need, solve a problem
• Attend to details: Small changes to the design can have a big effect on people.
• Simplify: Remove irrelevant information, but do not mask essential indicators and feedback
• Honest and understandable: Functions should be reflected in forms that make their states visible, changes predictable, and interactions intuitive
• Provide flexibility: People should be able to adjust, navigate, undo and redo, adopt shortcuts
• Consistency: The same label or action should mean the same thing in different situations — don’t deviate from well-defined conventions
• Anticipate needs: Provide options rather than require people to recall them. Choose thoughtful defaults because people often adopt initial settings
• Minimize memory demands: Interactions with technology should not disrupt the flow of activities unless necessary
• Consider adaptation: Adopt a systems perspective to identify otherwise unanticipated outcomes, particularly as people adapt to the changes in the system
• Fit the task to the person rather than the person to the task

Then you can do cognitive walkthrough as well:

• Is it likely that the person will perform the right action?
• Does the person understand what task needs to be performed?
• Will the person notice that the next task can be performed?
• Will the person under stand how to perform the task?
• Does the person get feedback after performing the task indicating successful completion?

5 usability dimensions

• Learnability
• Efficiency
• Memorability
• Less Errors
• Satisfaction