You develop a SQL Server Analysis Services (SSAS) tabular project. The tabular model loads data from a SQL Server 2012 relational database each day. You used to configure Reporting Services to issue…

Using the SSAS service account conflates service identity with data source access, violating separation of concerns and potentially granting broader permissions than needed.

Using personal domain credentials creates a dependency on an individual user - if that account's password changes or the user leaves, the connection breaks, making it unsuitable for automated daily loads.

Creating a dedicated Windows domain account specifically for data source access follows the principle of least privilege and separation of concerns. It ensures the connection is not tied to a personal user account or the broader SSAS service account, so credentials remain stable even if personnel change. This is the recommended SSAS impersonation model for scheduled data refresh scenarios.

SQL Server authentication uses a username/password login rather than Windows integrated security, which is incompatible with the challenge/response (Windows auth) connection model described in the question.