Human-Machine Interface (HMI) is a term that refers to the "layer" that separates a human that is operating a machine from the machine itself.

One example of a HMI is the computer hardware and software that enables a single operator to monitor and control large machinery remotely.

The HMI interface involves the flow of decision support information via

• visual cues - generally provided by a computer monitor
• audible cues - speakers, horns, walkie-talkies
• control actions - keyboards, buttons, switches

Multiple monitors, communication devices and control surfaces grouped together form a console or operator station. From a console, an operator scans information, receives notifications and makes control actions.

A control room may consist of one or more operator consoles.

Control rooms and operator stations can be found in many different applications such as

• Airport control tower
• Police or ambulance dispatcher
• Nuclear power plant

The design of cockpits in airplanes and helicopters involve highly specialized HMI designs. However consumer appliances such as washing machines or dishwashers also have a HMI.

Human-Machine Interface is a gender-neutral version of the term Man-Machine Interface (MMI). The abbreviation MMI is still in use although some who still use the term may claim that MMI stands for something different now (e.g. "Management and Manufacturing Information" or "Mammal-Machine Interface").

In science fiction, HMI is sometimes used to refer to what is better described as direct neural interface.

See also

• Human factors
• Ergonomics
• SCADA
• Programmable logic controller
• Human-computer interaction
• Distributed Control System
• Manufacturing
• Mouthpiece