The relational database (Microsoft SQL Server) that stores all the ERP-related transactions is known as online transactional processing (OLTP). For BI reporting with a SQL Server, SSAS can store the aggregations, measures, and dimensions. This results in a higher performance in querying reports. It is also important to consider backup and restore strategies.
Reports from Microsoft Dynamics 365 for Finance and Operations are based on the SSRS approach and Financial Reporting.