SQL Server Analysis Services (SSAS) is a critical technology for Power BI consultants when working with enterprise-scale data models. SSAS allows consultants to build multidimensional or tabular data models that Power BI can then connect to for reporting and analysis. Power BI consultant use SSAS to handle large datasets and perform complex calculations that would otherwise be inefficient directly in Power BI. By leveraging SSAS, consultants provide clients with optimized performance, scalability, and the ability to work with highly complex data structures.