In the EC machine directive they are referred to as “assemblies of machinery”, in the industry they are mostly known as plants. However we may call them, all of them need an instruction manual. It’s just the way it is.
Not all employees these days are able to look forward to a peaceful Christmas holiday and a few days off. When manufacturing stops, maintenance rolls up its sleeves. Machines are reconstructed, and “time pressure” is a latent companion. This can quickly lead to inattentiveness or even carelessness. Hardly anyone considers occupational safety and health.
The chapter “Maintenance” is an integral part of operating instructions. In the case of extensive regular work, the machine often even comes with its own maintenance instructions. Components must be oiled or checked at a weekly basis in accordance with the maintenance schedule.