The factory floor refers to the workers in a factory, as opposed to the managers. It can also refer to the area where they work.
He had worked on the factory floor for 16 years.
N-SING : the N
FACTORY FLOOR
Meaning of FACTORY FLOOR in English
Collins COBUILD Advanced Learner's English Dictionary. Английский словарь Коллинз COBUILD для изучающих язык на продвинутом уровне. 2006