What is the difference between a preventive maintenance task and a predictive maintenance task?

• A. Preventive maintenance is performed on a calendar schedule; predictive maintenance is based on equipment age.
• B. Preventive maintenance relies on condition monitoring; predictive maintenance relies on time-based scheduling.
• C. Preventive maintenance is time-based; predictive maintenance uses condition data to decide when to perform maintenance.
• D. Preventive and predictive maintenance are determined randomly.

Answer: (C)

The main idea is how maintenance timing is determined: preventive maintenance follows a fixed schedule, while predictive maintenance relies on actual condition data to decide when to act. Preventive maintenance is planned on a calendar or usage basis, so tasks happen at regular intervals whether the equipment shows signs of wear or not. This helps prevent failures but can lead to unnecessary service if the asset doesn’t actually need attention yet. Predictive maintenance, on the other hand, uses data from the equipment—such as vibration, temperature, oil analysis, and other condition indicators—to forecast when a component will fail and schedule maintenance just before that point. This approach aims to maximize uptime and minimize unnecessary work by acting based on real wear and performance trends rather than a fixed timetable. For example, a chiller might have a preventive task to replace a filter every 90 days, whereas a predictive approach would monitor sensor data to determine the optimal replacement time as conditions change. The other options either mix up which approach uses condition data, incorrectly attribute aging or randomness to maintenance decisions, or reverse time-based and condition-based concepts, which doesn’t align with how preventive and predictive maintenance are actually practiced.