Determining whether HMI (Human-Machine Interface) or SCADA (Supervisory Control and Data Acquisition) is "better" depends on the specific needs and requirements of the industrial automation project. Each serves a different purpose within an automation system:

1. HMI (Human-Machine Interface):

   • Better suited for local control and monitoring at the machine or equipment level.
   • Provides a graphical interface for operators to interact directly with machines or systems.
   • Typically offers features such as control buttons, status indicators, data visualization, and alarms.
   • Enables operators to have immediate access and control over specific processes.
   • Ideal for applications where localized control and quick decision-making are critical.

2. SCADA (Supervisory Control and Data Acquisition):

   • Better suited for supervisory control, data acquisition, and monitoring across entire industrial processes or facilities.
   • Integrates data from multiple sources, including HMIs, sensors, and other devices, providing a comprehensive view of the system.
   • Offers advanced features such as data logging, historical analysis, alarming, and remote access.
   • Enables operators to monitor and control complex processes from a centralized location.
   • Ideal for applications where system-wide visibility, data analysis, and remote access are essential.

In many cases, both HMI and SCADA systems are used together to create a comprehensive automation solution. HMIs provide localized control and monitoring at the machine level, while SCADA systems offer supervisory control and integration across multiple systems. The choice between HMI and SCADA depends on factors such as the scale of the operation, the complexity of the processes involved, and the specific requirements of the project.