Definition
A Human-Machine Interface is the part of a system that enables a person to receive information, issue commands and control the operation of a machine, device or technical system.
Human Explanation
An interface may be a screen, control panel, button, alarm, indicator or another element through which a person communicates with a machine.
Why it Matters
A well-designed interface makes system status easier to understand, reduces the risk of errors and enables faster responses to changes or hazards.
Conceptual Boundary
A Human-Machine Interface is not only the appearance of a screen. It also includes how information is presented, the arrangement of controls, alarm logic, action sequences and feedback.
Practical Perspective
If an operator must remember too many steps, interpret ambiguous messages or search for the most important information, the interface does not support human work sufficiently.