For data migration directly from an SAP ERP system to RISE with SAP S/4HANA Cloud, private edition, the use of Extract, Transform, and Load (ETL) tools is standard. This process involves extracting data from the existing SAP ERP system, transforming it to fit the new data structures of SAP S/4HANA, and then loading it into the SAP S/4HANA environment through a staging database. This method ensures data integrity and compatibility with the new system's architecture.References= This approach is outlined in SAP S/4HANA migration guidelines and supported by tools and best practices provided by SAP for ensuring a smooth transition.

In RISE with SAP S/4HANA Cloud, private edition, key-user in-app extensions allow for significant customization within the provided framework to meet specific business needs. Two such capabilities are defining custom tables through the Custom Business Objects SAP Fiori app, which enables users to create and manage their own database tables within the system, and creating custom application UIs with UI Adaptation at Runtime, which allows for modifications to the user interface of applications directly in the live system without traditional development processes.References= These features are outlined in the official SAP documentation for SAP S/4HANA Cloud, private edition, which describes the scope and capabilities of in-app extensions available to key users.

In RISE with SAP S/4HANA Cloud, private edition, roles are assigned to users primarily through the
"Maintain Business Users" SAP Fiori app. This tool allows administrators to manage user profiles, including the assignment of roles that control access to various functions and data within the system. This app provides a user-friendly interface for managing roles and permissions aligned with modern cloud-based environments.References= This method of role assignment is supported by SAP Fiori administrative guides and is part of best practices for user management in SAP systems.