Original sentence: Is Preventive Maintenance Necessary.PM is also sometimes augmented by reliability centered maintenance and predictive maintenance, both of which attempt to optimize the PM tasks.Preventive maintenance (PM) has the following meanings:.While preventive maintenance is generally considered to be worthwhile, it is important to note that there are risks involved when performing PM, such as equipment failure or human error, just as there are in any maintenance operation
Edited sentence: preventive maintenance (PM) has the following meanings: