Defect Repair vs Corrective Action vs Preventive Action

Corrective action, preventive action, and defect repair are commonly used terms in quality management. You must understand the nuances of these terms for a better understanding of quality management processes.

Defect repair is a relatively simple concept. However, differentiating corrective action and preventive action is a little difficult; in fact, the difference is so minuscule that many aspirants get confused.

These concepts are also very important from a PMP exam point of view, and you will likely see a few questions on this topic. 

Defect Repair vs Corrective Action vs Preventive Action

Let’s start with defect repair.

Defect Repair

According to the PMBOK Guide, 6th edition, a defect repair is an intentional activity to modify a nonconforming product or product component.

Defect repair is the process of repairing or replacing the defective part as needed. It is instant; you must act immediately once you have identified a defect. This process is performed when the product does not meet the quality requirements.

For example, during an inspection, you find a discrepancy in the deliverable. It is not conforming to the requirements.

If you can correct the defect, do it immediately; if not,  replace the deliverable.

Defect repair is also called corrections or rework by industry experts.

Example of Defect Repair

Let’s say you are manufacturing rods of 10 meters long. During the inspection, you find that the length of one rod is 10.5 meters. As per the quality requirement, this product is not acceptable.

Therefore, you remove this rod from the lot and replace it with another correct rod. The process is immediate and reactive, requiring a straightforward fix.

Corrective Action

The PMBOK Guide, 6th edition, defines corrective action as an intentional activity that realigns the performance of the project work with the project management plan.

In quality management, corrective action is a future response to the defect repair process. This forward-looking next step ensures that the error will not occur again.

For example, let’s say that you find some defective components and you corrected them. Since you don’t want this defect to happen again, you will find the root cause of the problem and develop a solution. Going forward, you will apply this solution to your processes so the defects do not occur again.

Corrective action helps you uncover and address the root cause of the problem and stops a recurrence of the deviation.

Corrective action is a reactive process that both addresses the immediate problem and prevents future issues.

Example of Corrective Action

You are manufacturing 10-meter long rods. While inspecting, you find some rods have different lengths.

You start investigating the root cause of this. You find that a bug in the code is causing the defective manufacturing process, so you contact the machine’s supplier and ask them to correct the code.

Technicians show up, modify the code, and now the machine is producing rods of the correct length.

This is an example of corrective action. The problem was solved and won’t happen again.

Preventive Action

According to the PMBOK Guide, 6th edition, preventive action is an intentional activity that ensures the future performance of the project work is aligned with the project management plan.

In quality management, preventive action helps avoid any future defects.

For example, let’s say that you are going to start a production process. You predict that some defects may appear during the production, so you review your processes and make necessary changes to prevent this.

Unlike Defect Repair and Corrective Action, which react to a problem, Preventive Action is a proactive process that prevents problems from arising.

In other words, the problem has already occurred in corrective action, and you are taking action to ensure that it does not reoccur.

In preventive action, a problem has not yet occurred, and you’re taking measures to make sure it never does.

Preventive actions help you find the cause of any future defects and to prevent them from occurring. They ensure that the deliverable is defect-free and ultimately save you and your project time, money, and hassles.

Example of Preventive Action

You are going to begin producing rods, but you then remember that, in your previous company, you faced an issue with the code for a similar process. This issue caused the rods to be of different lengths, and you are about to start using the same process with similar equipment in the current company.

You don’t want the error to occur this time, so you ask the programmers from your company to come and check the code. Thankfully, they do not find any errors.

Here you took preventive action to stop the error from occurring, and this cautionary step saved your project time and money.

How to Implement Defect Repair, Corrective Action, and Preventive Action

Whether you need to repair defects, take corrective or preventive action, use the change requests process, as some actions may require a plan modification and a slight change in the cost baseline.

Generally, the effect on the baseline is not significant.

However, the costs of defect repair, corrective action, and preventive action are borne by you. You cannot ask the client to pay for it. These are the costs of quality, which include the costs of conformance or nonconformance. The cost of defect repair and corrective action will fall under the cost of nonconformance. Preventive action costs are under the cost of conformance. You should consider these costs an investment in your reputation and the ultimate success of the project.


Defects in your products or processes are routine in project management; however, there is always a scope for improvement. Once the project starts, you will have to deal with different kinds of defects with unique processes to address them. 

Obviously, defect repair is about fixing the product. In preventive action, you try to avoid any defects that may appear in the future. In corrective action, you have found defects, and you act so the future products can be defect-free.

How do you deal with corrective action, preventive action, and defect repair? Please share your experiences in the comments section.