A human-machine system is a system in which the functions of a human operator and a machine are interrelated and necessary to achieve system goals and objectives. Increased sophistication of modern computer and automation technology has significantly changed the character of the human-machine system. The typical human role has shifted from performing direct manual control of elementary processes to the supervision of complex, capable and intelligent systems (for example, the flight management system used in aviation industry). Human-machine systems differ considerably in their purpose, structure and complexity, but in all cases, system design has to leverage the abilities of both the human and machine components and improve the overall performance of the system. However, as human-machine systems are becoming even more intricate due to increasing number of functions, inputs, outputs, decision elements, controls, displays, and symbols, the potential opportunities for errors also increase. Technology alone is too often seen as a panacea without taking into consideration sensory, cognitive and motor limitations of humans, environmental factors, organizational constraints, user interface design, and various workflow issues. Undeniably, the underlying complexity of healthcare processes affects the ability of healthcare professionals to maintain situational awareness, solve problems and perform tasks correctly. Improper introduction of new technology may exacerbate human performance problems, create new vulnerabilities, add new forms and levels of complexity to the already complex healthcare system, and further diminish its reliability. It is essential to adopt a human-centered approach to technology and work systems design while minimizing, monitoring, and controlling complexity of the system.
