What Is Corrective Maintenance?

Corrective maintenance is all about fixing equipment or system defects once they’ve been detected. It’s considered the most basic type of maintenance. Usually, it involves identifying issues during preventive maintenance checks and correcting or repairing them.

This type of maintenance takes place after a failure or malfunction has occurred—often without warning—so it can’t really be scheduled ahead of time. The costs can add up quickly: unexpected repairs, unbudgeted parts, and component replacements. And while sometimes it’s unavoidable, corrective maintenance can have a big financial impact on companies and often leads to extended equipment downtime.

That said, a significant portion of these breakdowns can be avoided with a solid preventive maintenance plan.

The ultimate goal of corrective maintenance is always to restore equipment functionality and avoid unexpected replacement costs.

Advantages of Corrective Maintenance:

• Doesn’t require a complex technical infrastructure or in-depth analysis

• Many equipment issues are well-documented, making repairs easier

• Often avoids needing to replace older equipment just to keep running

• Maximizes the useful life of machinery

• Doesn’t require elaborate planning—just fix what breaks as it happens

Disadvantages of Corrective Maintenance:

• Breakdowns are unexpected and disrupt production

• Risk of failure in hard-to-replace parts, requiring a well-stocked inventory

• Maintenance quality can drop due to time pressure

• Repair time may vary widely—and sometimes takes too long, causing serious losses

Types of Corrective Maintenance:

1. Unplanned Corrective Maintenance

Also called reactive maintenance, this happens when a machine fails suddenly—resulting in downtime. This can be due to early component failure or lack of performance monitoring. Either way, the response is chaotic because the repair becomes an emergency.

2. Planned Corrective Maintenance

This happens when you detect a drop in equipment performance and choose to act before total failure. These interventions aren’t emergencies and can be scheduled appropriately.

However, even a machine with reduced performance causes losses in two ways:

• You lose productivity due to poor performance

• You’re essentially sitting on a ticking time bomb—it could fail completely at any moment

When Does Corrective Maintenance Make Sense?

Some typical scenarios where corrective maintenance is a reasonable choice:

• When the cost of downtime is lower than the cost of regular preventive actions—usually in secondary systems that don’t significantly affect production.

• It’s statistically the most used method across industries.

• When you have multiple spare parts available and can replace components quickly when needed.

• When decreased performance doesn’t create safety issues or drastically hurt overall productivity.
  However, as soon as a performance drop is detected, maintenance should be scheduled as soon as possible to avoid major issues.

Real-World Example: Isolated Electrical Systems

In isolated electrical systems, certain failures can be repaired quickly. For example:

• Voltage levels that are too high or low for medical devices

• Errors from the line isolation monitor or other malfunction indicators

• High leakage current

• Malfunctioning breakers

• Faulty receptacles

Final Note: Don’t Confuse Corrective Maintenance with Emergency Maintenance

These two happen at different stages of failure.

• Corrective maintenance is performed when there’s a noticeable issue or functional failure.

• Emergency maintenance happens after a total breakdown—when urgent action is required, usually at a much higher cost.