Human Factors Engineers in Sacramento are the professionals who apply the knowledge of human capabilities & limitations for designing of products, processes, working environments & systems having a human interface. Their basic roles are improvement of the ease of use, enhancement of system performance, improving reliability, providing user satisfaction, reduction of operational errors, operator stress, training requirements, user fatigue, and product liability. Human factors engineers relate humans to technology. They focus on the way people interact with tasks, machines, and the environment with the consideration that humans have limitations and capabilities. The various activities of Human Factors engineers include: usability assurance, determination of desired user profiles, development of user documentation and development of training programs.