CAPA is a fundamental management tool that should be used in every quality system.

Corrective Actions 
 A corrective action is a term that encompasses the process of reacting to product problems, customer complaints or other nonconformities and fixing them. The process includes:
  • Reviewing and defining the problem or nonconformity
  • Finding the cause of the problem
  • Developing an action plan to correct the problem and prevent a recurrence
  • Implementing the plan
  • Evaluating the effectiveness of the correction.

Preventive Actions
A preventive action is a process for detecting potential problems or nonconformance’s and eliminating them. The process includes:
  • Identify the potential problem or nonconformance
  • Find the cause of the potential problem
  • Develop a plan to prevent the occurrence.
  • Implement the plan
  • Review the actions taken and the effectiveness in preventing the problem.

Differences between Corrective and Preventive Actions 

The process used for corrective actions and preventive actions is very similar and the steps outlined in this document can be used for either. However, it is important to understand the differences and also be aware of the implications involved in performing and documenting each.

Corrective Action
A corrective action is a reaction to a problem that has already occurred. It assumes that a nonconformance or problem exists and has been reported by either internal or external sources. The actions initiated are intended to: a) fix the problem and b) modify the quality system so that the process that caused it is monitored to prevent a reoccurrence. The documentation for a corrective action provides evidence that the problem was recognized, corrected, and proper controls installed to make sure that it does not happen again.
To address the Corrective Action clause you should be identifying the root cause of non-conformances that have already taken place and implementing immediate corrective actions to contain the situation and long term corrective actions to prevent their re-occurrence.

For example, in a manufacturing setting, a large batch of subassemblies produced four weeks ago was found to be out of specification when received for final product assembly. In this situation a problem exists and has been identified. A corrective action must be implemented to avoid production delays and a possible financial impact on the company.

Preventive Action
A preventive action is initiated to stop a potential problem from occurring. It assumes that adequate monitoring and controls are in place in the quality system to assure that potential problems are identified and eliminated before they happen. If something in the quality system indicates that a possible problem is or may develop, a preventive action must be implemented to avert and then eliminate the potential situation. The documentation for a preventive action provides evidence that an effective quality system has been implemented that is able to anticipate, identify and eliminate potential problems.

It is often seen that organisations are raising preventive actions as a result of a non-conformance and after they have identified corrective actions. Because they see the word “Preventive” within the clause they believe this means to prevent the non-conformance from re-occurring.

Types of Preventive Actions can include processes such as performing risk assessments against product, processes and health and safety activities. You are aiming to prevent a non-conformance from ever occurring by taking preventative measures.

Most organisations take Preventive Actions without knowing they are. Within the construction industry you will commonly see kick off and progress meetings throughout projects, these are preventive actions as the members present at the meeting will be discussing potential problems which may hold back the progress of the project.

Observations raising during internal audits could be classed as Preventive Actions as they can suggest improvements within the system to prevent non-conformances from occurring in the future.
Customer feedback is another method that can be used as Preventive Action evidence as customer suggestions may prevent any issues from being raised in future with regards to the service or product you provide.

For example, Statistical Process Control has shown that over a period of several weeks a machining process has slowly but consistently trended toward the upper control limit. This situation would likely require a preventive action to assure that the process does not get out of control resulting in scrap and/or defective parts and, again, a possible financial impact on the company.

You can clearly see from the excerpts taken from the ISO 9001 standard that Corrective Actions are taken as a result of non-conformances whilst Preventive Actions are taken against potential non-conformances to prevent them from ever occurring.

You should not be raising Preventive Actions after a non-conformance has occurred, you should only be raising Corrective Actions.

A timely, well documented, Corrective / Preventive Action program validates a quality system that is not only capable of identifying potential problems but also effectively correcting them when they do occur.