In CMMS, what is the difference between preventive maintenance and predictive maintenance?

• A. Preventive maintenance uses fixed schedules; predictive maintenance uses condition data to trigger maintenance before failure.
• B. Predictive maintenance uses fixed schedules; preventive uses condition data.
• C. They are the same.
• D. Preventive maintenance uses fixed schedules; predictive maintenance uses condition data to trigger maintenance before failure.

Answer: (D)

The main idea here is how the maintenance is decided: by time or by asset condition. Preventive maintenance is planned on fixed schedules or usage milestones, meaning work is done regularly even if the asset shows no signs of wear. Predictive maintenance, on the other hand, relies on condition data collected from the asset—such as sensors, diagnostics, or inspections—to estimate when a component will fail and trigger maintenance just before that failure.

In CMMS, preventive maintenance might be things like lubricating every three months or replacing a filter every six months, regardless of current condition. Predictive maintenance uses data trends (for example, rising vibration, increasing temperature, or deteriorating oil analysis) to forecast remaining useful life and schedule service before a fault occurs. This makes predictive maintenance more dynamic and condition-driven.

So the best description is that preventive maintenance uses fixed schedules, while predictive maintenance uses condition data to trigger maintenance before failure.