The concept of preventive maintenance has a multitude of meanings. A literal interpretation of the
term is a maintenance program that is committed to the elimination or prevention of corrective and breakdown maintenance tasks. A comprehensive preventive maintenance program will utilize regular evaluation of critical plant equipment, machinery, and systems to detect potential problems and immediately schedule maintenance tasks that will prevent any degradation in operating condition.

In most plants, preventive maintenance is limited to periodic lubrication, adjustments, and other
time-driven maintenance tasks. These programs are not true preventive programs. In fact, most continue to rely on breakdowns as the principal motivation for maintenance activities

A comprehensive preventive maintenance program will include predictive maintenance, time-driven
maintenance tasks, and corrective maintenance to provide comprehensive support for all plant production or manufacturing systems.