@Hans Andersen , Open the System Info on the taskbar of the application. Then place the cursor on the Employee ID field. You will see the required info on the System Info. But, I cannot see this employee id field on the standard core application. I doubt whether this is a custom field on the shop floor workbench itself?

I suspect information about the employees currently logged in to the workbench is only stored on the client. I that case I cannot find it through SQL (as with the user_id: fnd_session_api.Get_Fnd_User()).

@Hans Andersen please send me a screen shot after opening the system info and placing the cursor on the Employee ID field

Sure.