Corrective maintenanceHow to swap corrective work for preventive maintenance
What is corrective maintenance?
There are three situations when corrective maintenance occurs:
- When an issue is detected through condition monitoring
- When a routine inspection uncovers a potential fault
- When a piece of equipment breaks down
Types of corrective maintenance
Corrective maintenance is separated into planned and unplanned tasks.
Planned corrective maintenance
There are two ways that corrective maintenance can be planned.
- Corrective maintenance is planned when a run-to-failure maintenance strategy is used. This is when an asset is allowed to run until it breaks down and is then repaired or replaced. This type of corrective maintenance only works with non-critical assets that are easily and cheaply repaired or replaced, or with systems that have redundancies.
- Corrective maintenance is planned when it’s performed as part of preventive maintenance or condition-based monitoring. Both preventive and condition-based maintenance attempt to find problems before they cause equipment failure. If a problem is found, maintenance can be planned and scheduled.
Unplanned corrective maintenance
Corrective maintenance is considered unplanned in two situations.
- Corrective maintenance is unplanned when a preventive maintenance schedule is in place, but a breakdown occurs between scheduled maintenance actions. Maintenance can be may be performed immediately or at a later date, depending on the availability of tools, parts, and personnel.
- Corrective maintenance can also be unplanned when an asset shows signs of potential failure or reaches failure unexpectedly. In this scenario, there are no planned maintenance actions to catch the failure before it happens or to address it after it happens.
Examples of corrective maintenance
There are several different scenarios where corrective maintenance can be used. These examples can be split up into planned and unplanned tasks.
Examples of planned corrective maintenance
- Imagine an asset has several fans. The asset can still operate properly if one breaks and there are lots of extra fans in your storeroom, which means repairs are quick and inexpensive. Because of this, you decide to let the fans run until one of them fails and then replace it at that point. This is an example of run-to-fail corrective maintenance.
- Let’s say you perform a preventive maintenance inspection on a conveyor system every two weeks. During one of these inspections, you find that some bearings have been damaged, so you replace them. This is an example of preventive corrective maintenance.
Examples of unplanned corrective maintenance
- Pretend your facility has a compressor. You plan for it to be inspected and repaired after every 100 hours of use in order to keep it functioning properly. However, the asset breaks after only 75 hours of operation and you have to perform an emergency repair. This is one example of unplanned corrective maintenance.
- Unplanned corrective maintenance can also happen if you have no plan in place to maintain, repair, or replace a piece of equipment before it fails. For example, your facility can’t afford for one of its forklifts to break down, but there’s no preventive maintenance done on the vehicles. When it breaks and a technician scrambles to get it working again, this is considered unplanned corrective maintenance.
When to use corrective maintenance?
Corrective maintenance can improve asset health and performance in situations when planned maintenance occurs.
- When preventive maintenance tasks identify potential faults
- When condition-based monitoring finds machine anomalies that signal potential failure
- When non-critical assets can be allowed to run to failure and are inexpensive and easy to repair or replace.
- When asset failure doesn’t affect safety
- When a system has redundancies that allow it to operate properly even if a part fails
In order to get the most benefit from corrective maintenance, organizations must provide training to maintenance employees about what to look for when they are carrying out preventive maintenance duties. Planning for corrective maintenance—by making sure that needed parts and equipment are always available, for example—can also ensure that corrective maintenance happens before disaster strikes. By maximizing planned corrective maintenance, organizations can reduce unplanned corrective maintenance and the costly downtime that comes with it.