Which maintenance category is focused on avoiding unplanned downtime by acting before a failure is detected?

• A. Corrective
• B. Predictive
• C. Reliability Centered
• D. Preventative

Answer: (D)

Preventive maintenance focuses on keeping equipment running by performing planned service on a schedule before wear or conditions lead to a failure. The idea is to act ahead of problems so unplanned downtime doesn’t occur, using known failure patterns, manufacturer recommendations, and usage milestones. By lubricating moving parts, replacing components at set intervals, cleaning, and inspecting for signs of wear, you head off issues before they impact reliability, which keeps systems available and productive.

This approach contrasts with corrective maintenance, which kicks in after something already failed and downtime has occurred. Predictive maintenance is also proactive, but it relies on monitoring data to detect early signs of deterioration and trigger work when indicators show a problem is developing. Reliability Centered Maintenance is a broader decision framework that guides what to maintain based on system function and risk, rather than a single proactive approach.