Maintenance keeps a work truck capable of doing its assigned job, not merely capable of driving to the site. The chassis may be roadworthy while a damaged compartment latch, unreliable liftgate, or failed equipment power supply prevents the crew from completing the work. A useful maintenance plan covers both the vehicle and the fitted body and equipment.
Work also creates demands that the odometer cannot fully represent. A truck may spend hours operating stationary equipment, make repeated short stops, carry a persistent load, or face dust and wet conditions. Match service to the actual use and the relevant manufacturers' instructions, then connect reported defects to repair and return-to-service decisions.