Proactive asset maintenance should be part of your maintenance plan as proactive maintenance can result in significant cost savings. It is different from reactive maintenance and preventive maintenance.
Preventive maintenance will try to perform repairs or parts replacement based on a maintenance schedule. Proactive maintenance will look at why machines break down. It may identify poor quality lubricant as a cause of failure, a technician not seating a gasket properly as another failure cause and so on. Fixing this will cut costs more than just preventive maintenance by itself.