The supernumerary staff in public institutions refers to the fact that in state-owned enterprises and institutions, many people who can't be recruited are hired, and these people can't enjoy the treatment and benefits that the hired people deserve, just like "doing odd jobs". Such people are called "supernumerary personnel".
"supernumerary personnel" is only relative to "supernumerary personnel". In the specific operation of government organs, institutions and state-owned enterprises, it is often the editorial board at a higher level that issues a "three-set plan" for government organs, enterprises and institutions, that is, defines functions, posts and personnel. This "staffing" is staffing. The office expenses, wages and benefits of these workers are guaranteed by the government.