Corrective and Preventive Action in 8D Problem Solving

[neash83]

Hello all,

I have a query regarding 8D and more specifically corrective and preventive action within 8D.

My understanding is that a lot of organisations use 8D as the basis of management and control of nonconforming product.

The one aspect of it I?ve never really got my head around is how 8D includes preventive action as one of the steps. I understand you have for example some nonconforming product; you contain it, complete some correction, and investigate the root cause. Then next you have the corrective action and the preventive action.

My interpretation of corrective action being action to prevent an something that has occurred from occurring again and preventive action being action to pre-empt a potential fault and stop it happening at all.

So my question is how can you complete corrective and preventive action with regards to 8D and some nonconforming product you have if the fault has already occurred? Doesn?t any action you put in place after the nonconforming product occurrence always have to be corrective?

How can it be preventive action if its already occurred?

Thanks

 

[Jen Kirley]

Good day neash83,

As shown on Wikipedia's explanation, D7 is "Take Preventive Measures: Modify the management systems, operation systems, practices, and procedures to prevent recurrence of this and all similar problems."

So the prevention aspect is in preventing both this exact issue from happening again, and other similar issues from happening in the first place.

I hope this helps!

 

[neash83]

Hello,

I understand that, but surely if the problem has already occurred any action you do subsequent to that is corrective action? I appreciate it may be simply semantics .

Regards

 

[Jim G]

Hi
Preventive action is taken to prevent occurrence whereas corrective action is taken to prevent recurrence.

After determining your root cause you are required to implement actions to prevent further escapes and read across to other potential problems.
Jim

[We learn more by looking for the answer to a question and not finding it than we do from learning the answer itself.]-Lloyd Alexander

 

[rob73]

As jennifer says, it is the application of the action to areas where the issue has not yet happened that makes it a preventative rather than corrective action.
For example: I have a car its tyre (or tire if you a yank) is bald so I replace it - corrective action, my motor bike tyre is not bald but I plan to replace it in one month to stop it going bald - preventative.

 

[shamhaider]

Preventive actions must be taken to prevent similar failures down the road..
It is considered as permanent solution to the existing problem..and also help in identify similar problems in other processes..

 

[qusys]

Hello,

I understand that, but surely if the problem has already occurred any action you do subsequent to that is corrective action? I appreciate it may be simply semantics .

Regards

In 8D you can assume that D7 is dedicated to the assessment of the things to be modified based upon the corrective action in whatever system, procedure, method , equipment, material of the organization. it represent a continuum of the corrective action. It is a question of words.
Preventive action is when you act on a "potential" non conformity

 

[Bev D]

Beyond the rather limited use of 8D for preventive action to prevent occurrence of the specific Problem under investigation in other similar products or processes, 8D is simply not a good tool for preventive action before a problem occurs.

FMEA is a rather decent tool for assessing whether preventive action is appropriate.

We must remember that there is no single tool that does it all.

 

[Helmut Jilling]

Beyond the rather limited use of 8D for preventive action to prevent occurrence of the specific Problem under investigation in other similar products or processes, 8D is simply not a good tool for preventive action before a problem occurs.

FMEA is a rather decent tool for assessing whether preventive action is appropriate.

We must remember that there is no single tool that does it all.

I find the 8D format is a perfectly useful tool for Preventive Action, if you follow the classic approach described in cl 8.5.3.

To use it, look for POTENTIAL issues in your system, or in production. If it is significant, begin to fill out the form as you would if you were doing a corrective action. The only difference is the verb tense will say things like "could happen" instead of "did happen."

Same root causes, same actions, etc.

 

[Miner]

Jennifer has the correct interpretation.

Do not confuse the 8D concept of Preventive Action with the ISO 9001 definition of Prevention. They are NOT the same. Ford developed the Team Oriented Problem Solving (TOPS)/8D/Global 8D methodology many years before ISO 9001 became common place. They had a different perspective on prevention.

To Ford, Corrective Action is action taken on the root cause of the problem itself as well as the root cause for the escape. These are the first two branches of the 5 Why. Ford defines Prevention (from the 8D perspective) as actions taken on the systemic root cause of the Quality Management System that allowed either or both of the problem/escape root causes to occur (3rd branch of 5 Why) as well as "Extending the Fix" to similar products/processes that contain the potential for the same root cause to occur.

The ISO 9001 definition of Prevention is an entirely different animal from the 8D definition.