What is unscheduled service to correct unexpected failures on equipment called?

Unscheduled service to correct unexpected failures on equipment is referred to as emergency work. This type of work is necessary when equipment breaks down or fails unexpectedly, requiring immediate attention to restore operations and prevent further disruption. Emergency work is typically unplanned and arises from unforeseen circumstances that can impact the safety, functionality, or operation of systems or equipment.

In contrast, preventive maintenance involves routine inspections and maintenance tasks performed to prevent equipment failures before they occur, while scheduled maintenance consists of planned tasks conducted at regular intervals. Regular maintenance is often synonymous with these planned activities. Emergency work specifically addresses urgent, unanticipated issues rather than routine upkeep or proactive measures, making it the appropriate term for correcting unexpected failures.