Monitor the oil's working temperature. Hot oil lowers viscosity, increases internal leakage and shortens seal life. Check the oil cooler and its water flow regularly.
Replace filters on schedule and take the clogging indicator seriously.
Periodic oil analysis (particles, water, acidity) shows when a change is really needed and whether a component is wearing.
This note is general guidance. For exact settings, the material datasheet and the machine maker's instructions are the reference.