Mileage, engine hours, and calendar time measure different kinds of wear. Track trucks by odometer, powered equipment by hour meter, and trailers or seasonal work by date. Use the exact manufacturer manual for each model and operating condition, then review every clock in one weekly due list.
On Friday, record every odometer and hour meter, log completed service, and look two weeks ahead. On Monday, release only job-ready assets. Once a month, compare service cost and repeat failures by asset.