An SAP retention system is essential for companies that want to decommission their legacy systems in compliance with legal requirements after an SAP S/HANA or SAP RISE migration. It ensures that data from previous SAP systems remains secure and available, protects sensitive information, and supports companies in complying with legal requirements and optimizing their IT landscape. The data in the retention system is protected against unauthorized access and cannot be changed but remains accessible for the continuation of business transactions.