• 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.

Task analysis is a broad term that encompasses many other techniques such as use cases, user stories, and user journeys. All of these techniques focus on understanding

• Why - users’ goals and motivations
• What - the tasks and subtasks to achieve these goals
• When - the ordering and timing of these tasks
• Where - and the location and situation

Change what operators do than on 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.

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