Automatically Assign a Category to Uncategorized Rows in Power Query and DAX

A data engineering problem involves assigning an organizational unit (OU) to unassigned office seats based on specific business rules. The primary rule is to assign the OU that owns the most seats within the same room, or fallback to the most dominant OU on the entire floor if a room has no assigned seats. An initial solution using Power Query M-functions worked locally but failed in production due to severe performance degradation over network drives and limitations with dynamic data sources in the Power BI service. The successful and more robust solution was implemented using DAX calculated columns to first identify the latest dataset and then apply the complex assignment logic by counting and ranking OUs within the proper context.