Correction, Corrective Action and Preventive Action
A critical requirement of ISO 9001 is corrective & preventive action (Sec. 8.5.2-8.5.3), and we are often asked the difference. Here is a quick evaluation and example to help you:
ISO 9000:2005 Sec. 3.6 defines them as follows:
- Correction - Action to eliminate a detected nonconformity
- Corrective action - Action to eliminate the cause of a detected nonconformity
- Preventive action - Action to eliminate the cause of a potential nonconformity
To expand on these definitions a bit
- Correction: When a problem occurs, you need to keep several aspects in mind.
- Determine the magnitude of the problem.
- Determine how to prevent it from getting bigger.
- How to address current situation.
You could call this - Damage Control. Although this correction takes steps to correct the problem it has no bearing on cause.
- Corrective Action: Now determine if the importance of the situation requires further action:
- Was it a big deal?
- What's the chance it will happen again?
- Estimate of any future threat
The causes need to be looked into to prevent recurrence if it was a big deal.
- Preventive Action: First you need to assess the risk and mitigate it based upon severity. The following tools are helpful: Source: Carnegie Mellon University
- FMEA - Failure mode & effects analysis
- Hazard and operability analysis (HAZOP)
- Fault tree analysis (FTA)
- Correction & Corrective Action -
- HIGH risk/impact/frequency
- Correction fixes the CURRENT set of issues
- Corrective action prevents it from happening again by looking at causes
- LOW risk/impact actions are similar since likelihood of recurrence is low
- Corrective & Preventive Action - the damage is already done in corrective action
Simple Example to demonstrate the differences
A customer orders 500 parts, but only 450 are delivered.
- Correction - Fix the current issue
- get the customer 50 more parts
- Corrective Action - Why were we short?
- Operator miscounted 9 boxes of 50 as 10 boxes of 50
- Preventive Action - make sure it doesn't happen again
- Weigh products on scale so you know if quantity is met
ISO 9001 requires the organization to have a documented procedure for corrective an preventive action.
Note: The combination of corrective action and preventive action documented procedures into a single QMS document is acceptable, but is not recommended. If these are combined, then it is important to verify that the organization understands clearly the difference between the intent of corrective and preventive actions.