The 'Average Headcount' measure in WFA is showing multiple rows per employee when Drill to Detail is selected.
SAP Success Factors Workforce Analytics (ANA) - All versions
This is expected behaviour.
Average Headcount has to take into account all parts of the month for each employee, and if anything changes during the month there will be more than one record.
For example, the employee was promoted, demoted or transferred, their position (or any attribute of that position) could change, they could acquire a disability, and so on.
This is true with or without WFA on HANA.
In order to retrieve a single record per employee for each month, use SOP or End of Period (EOP) measure instead.
Like EOP Headcount or EOP FTE, there is an EOP flag which DTD is able to filter on.
WFA, Average Headcount, WFA on HANA, Drill to Detail, DTD , KBA , LOD-SF-WFA-WA , Workforce Anaytics , How To