IEC 63303:2024 details the core architecture and operational aspects of Human-Machine Interface (HMI) systems. The document also incorporates a case study illustrating the lifecycle of an HMI. It establishes the necessary requirements and suggestions for actions throughout the various phases of the HMI system’s lifecycle, such as the design, deployment, and upkeep of the system. Furthermore, it sets forth criteria for the functionality and performance of HMI systems. The instructions contained in this document are relevant to all controlled processes that employ an HMI for interaction with a control system. Variations in the application of these guidelines may be necessary to accommodate the unique requirements of different applications and types of controlled processes.