The Human Machine Interface (HMI) is the interface between the process and the operator; It is basically an operator’s instrument panel. It is the main tool used by operators and line supervisors to coordinate and control industrial and manufacturing processes. The HMI translates complex process variables into useful and actionable information.

The function of HMIs is to display operational information in real time. They provide visual process graphics that provide meaning and context to the state of the engine and valve, reservoir levels and other process parameters. They provide operational information to the process, and allow control and optimization by regulating the production and process objectives