What is preventive maintenance (PM)?

• A. Scheduled maintenance designed to prevent equipment failures and ensure reliability.
• B. Maintenance based on real-time data to trigger actions.
• C. A safety device preventing unintended movement.
• D. A plan to route trains.

Answer: (A)

Preventive maintenance is scheduled maintenance designed to prevent equipment failures and ensure reliability. It involves planned inspections, adjustments, lubrication, part replacements, and tests at predefined intervals or after a certain amount of use, before a fault shows up. This proactive approach aims to keep equipment operating safely and efficiently and to reduce unexpected downtime.

That’s why the described option is the best fit: it emphasizes planned, routine work performed to prevent failures and maintain reliability. Other ideas described here point to different maintenance philosophies—using real-time data to trigger actions (condition-based maintenance), a safety device, or a routing plan—which aren’t preventive maintenance.