Compare preventive maintenance and corrective maintenance.

Compare preventive maintenance and corrective maintenance.

• A. Preventive maintenance is performed after a failure to fix the item.
• B. Corrective maintenance is planned and scheduled ahead of time regardless of condition.
• C. Preventive maintenance is performed only after a device fails.
• D. Preventive maintenance focuses on preventing failures via scheduled checks; corrective maintenance repairs items after a failure.

Answer: (D)

The main idea is how maintenance types differ in timing and purpose. Preventive maintenance is a proactive, planned effort to prevent failures by regularly inspecting, servicing, and replacing parts before they fail. Corrective maintenance is reactive, focused on restoring function after a failure or defect is detected. The best description combines these ideas: preventive maintenance aims to prevent failures through scheduled checks, while corrective maintenance repairs items after a failure has occurred. The other statements mix up timing or purpose—for example, suggesting preventive work happens only after a device fails, or that corrective work is scheduled regardless of condition—so they miss the essential proactive vs. reactive distinction.

The main idea is how maintenance types differ in timing and purpose. Preventive maintenance is a proactive, planned effort to prevent failures by regularly inspecting, servicing, and replacing parts before they fail. Corrective maintenance is reactive, focused on restoring function after a failure or defect is detected. The best description combines these ideas: preventive maintenance aims to prevent failures through scheduled checks, while corrective maintenance repairs items after a failure has occurred. The other statements mix up timing or purpose—for example, suggesting preventive work happens only after a device fails, or that corrective work is scheduled regardless of condition—so they miss the essential proactive vs. reactive distinction.