Machine and plant operators prepare work processes, check machine functions on test benches and put machines into operation. These can be, for example, tool, textile, printing machines or systems for food and beverage production. They monitor the production process and control or monitor the flow of materials. They also inspect or maintain machines at regular intervals to ensure that they are ready for operation. For example, they refill oils or coolants and lubricants. They replace wearing parts such as seals, filters or hoses.