Which term describes scheduled maintenance designed to keep equipment running efficiently by preventing breakdowns before they occur?

• A. The process of diagnosing the source of a problem and resolving issues within a system or machine.
• B. Scheduled maintenance designed to keep equipment running efficiently by preventing breakdowns before they occur.
• C. The provision of fresh air to a room, building, or other enclosed space, or the removal of stale or contaminated air.
• D. A set of step-by-step instructions compiled by an organization to help workers carry out routine operations.

Answer: (B)

Preventive maintenance is the proactive, scheduled upkeep of equipment to prevent failures before they occur. This option describes exactly that idea: planned maintenance aimed at keeping equipment running efficiently and avoiding breakdowns in advance. In practice, it means regular inspections, servicing, and replacements based on time or usage to catch issues early and maintain safe, reliable operation—especially important for flammable-refrigerant systems where failures can have serious consequences. The other statements refer to different concepts: diagnosing and fixing problems (troubleshooting), providing ventilation (air exchange), and following step-by-step instructions (standard operating procedures), none of which capture the proactive, preventive maintenance focus.