Thursday, June 2, 2011

Correction , Corrective Action and Preventive Action with illustrations

As according to ISO Quality Management Definitions

"Correction is any action that is taken to eliminate to a nonconformity. However corrections do not address the causes. When applied to products, corrections can include reworking products, reprocessing them, assigning them to a different use , or simply destroying them."

Corrective Action 
"Corrective actions are steps that are taken to remove the causes of an existing non conformity or undesirable situation to prevent the recurrence of non conformities and situations. It tries to make sure that existing non conformities and situations don't happen again. It tries to prevent recurrence by eliminating causes. Corrective actions address actual problems. Because of this, the corrective action process can be thought of as a problem solving process."

Preventive Actions
"Preventive actions are steps that are taken to remove the cause of potential non conformities or potential situations that are undesirable. 
The prevent action process is designed to prevent the occurrence of non conformities or situations that do not yet exist. It tries to prevent occurrence by eliminating causes.While corrective actions prevent recurrences preventive actions prevent occurrence. Both types of actions are intended to prevent non conformities.
Preventive actions address potential problems , ones that haven't yet occurred, In general the preventive action process can be thought of as a risk analysis process."

Refer to the link below for the above definitions

I would like to explain all three by the following illustrations.

Illustration 1: Accident of School Student
A school was situated across the road , the traffic on the road is usual during the open and close time of the school. One day a student was hit by a biker when the students were coming to school in the morning. The boy was hit badly. All other students gathered there along with school staff and immediately the student get first ad and sent to the hospital to stop the blood flow from the injuries, this action describes as correction in which no further damage could happen to the student. Now this happening was reported to the principal of the school the principal call the meeting of all the school staff along with the biker for finding the root cause of this mis-happening , in the meeting it was found that biker was over speeding and due to this the accident happened. So over speeding was the cause of the accident, then principal ordered the school authorities that they would take corrective actions to prevent recurrence of such kind of  mis-happening. School authorities  introduced  a sign board before 15 metre of both  sides of school gate on road side on which speed limit mentioned as  20 km/hr along with the sign of school ahead. Also the breaker near the gate of school on road both sides so that this event could not recur in future. After taking the meeting the principal reported this happening to the municipal corporation and suggest that they should take such kind of preventive actions for all the school so that this kind of happening could not occur in the future. Municipal corporation access the risk of over speeding and the corporation take all the measure as preventive action  like Zebra crossing on the road, introduction of speed breaker on the road before the school, sign board of school along with speed limit introduced outside every school. Corporation also instructed all the school that they must deploy a person who control the traffic during  open and closing time of school.

Illustration 2 : Family Planning 
A couple complete their family with a boy and a girl. One day the wife give news to her husband about  third pregnancy but they don't want this pregnancy to deliver as this pregnancy was unwanted.So both of them go to a doctor. Doctor advise them that they should abort it as correction and if they don't want recur the pregnancy then they should use the contraceptive methods like condom, pills etc. to avoid unwanted pregnancy as corrective action as the doctor find this was due to the cause of unprotected sex. The couple came to their home and analyse the risk of having  third child. They find that if they have third child they have to share there love to three children instead of two , some more extra resources and care needed  in future. So they decided that they don't want  third child. They go to the doctor and wife has an operation as a preventive action  for permanent solution to avoid risk of  pregnancy in future.

Illustration 3 : In a manufacturing industry.
Consider a case of a manufacturing industry. Suppose in a  lot  quality inspector find a defected piece more than acceptable limits then as a correction he hold the lot for reworking to sort out that defective piece from the lot so that no customer complaint could generate.Along with this he instructed to the machine engineer that he should take corrective action for that defective piece i.e. he should check the die of the particular piece and replace it from other good one so that defect could not recur again. Machine engineer sent the die to design department for finding the root cause of the defect and analysis the defect occurrence  so that they could permanently eliminate it as preventive action and in future such kind of defect not occur also in  other dies.

Illustration 4 : Virus in computer.
Suppose a virus has entered in a computer system. Immediate  scanning of virus and removing it from the system is the correction to avoid further damage to the file stored  in the system.
As a corrective action find the site where the virus came and block the site so that virus could not come again into the system.
As a preventive action analysis the risk of damage to the system from all such kind of viruses and sites from which the viruses belongs and block all such sites so that such kind of threat could not come into the system and no potential damage to the system could occur.

I hope above mentioned Illustrations are sufficient to understand the correction , corrective action and preventive action. If you have such kind of illustration then you are most welcome to share.

Thanks and Regards
Narender Sharma

Comments are welcome.......!


Anonymous said...

Actually there is no difference between correction & corrective action. If something wrong happens and it is corrected, It comes under correction / corrective action. eg. the cutting edges of a blade got blunt much prior to its actual life because the coolant flow was not there. Replacing the blade and turning on the coolant is corrective action or correction. But if the root cause of coolant getting turned off is analyzed and eliminated like - pump not working / Level of coolant not adequate / Ignorance etc. are all eliminated through fool proofing method, it is said to be taken the preventive action. i.e. an action which will prevent the happening of the problem in future.

The difference mentioned above in blog is not correct.

Stephen Morris said...

These examples are a good way of explaining these terms. In my experience, the distinction between corrective and preventive actions was the least understood, even for me.

I sometimes find it helpful to think of preventive actions taking place at the design stage of the product, process or service. In others words, potential failures are anticipated and then designed out of the product, process or service before they happen.

Narender Sharma said...

Correction : Fix the problem
Corrective Action :Finding root cause of the problem and remove it.
Preventive Action : Finding Potential Root cause and remove it so that problem will not appear in future.

Mocona47 said...

To do prevention we work with 6 sigma.
But all is question of cost. Sometime it is less expensif to do correction.

Francis Owusu said...

There is a small difference between correction and corrective action. Though in some cases they could be comparable, it is important to differentiate them. In the automotive for instance, when making 8D, the correction can be seen as containment, where you bring couple of actions to keep delivery with only good parts to customer. e.g visual sorting...
We only talk about corrective action when a root cause have been defined. Then corrective actions are brought to eliminate the root of the problem.
As for preventive action, you transversalize corrective actions to similar process by looking for potential similar failure and re-enforcing lessons learned tools such as FMEA.

The first comment made by the anonymous is not correct!

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