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Corrective vs. Preventive Action
by Russ Westcott
Quality professionals frequently express confusion as to the difference between corrective and preventive action. A corrective action deals with a nonconformity that has occurred, and a preventive action addresses the potential for a nonconformity to occur. Many ISO 9000 registrar auditors tell their clients to use separate procedures and forms to document each type of action. Nothing in the standard says this must be done, but p. 13 includes the word “prevent” in the clauses on corrective and preventive action.
On closer reading, however, section 8.5.2 says corrective action eliminates the cause of nonconformities to prevent recurrence, and section 8.5.3 says preventive action determines and eliminates the causes of potential noncon- formities … to prevent occurrence. See, there is a difference!
There are three common misconceptions about corrective and preventive action:
- The standard calls for documenting every occurrence of a nonconformity.
- A preventive action is really just calling a corrective action something different.
- The major reengineering of a process, product or service, or the introduction of a new process or equipment, is not a candidate for preventive action documentation.
One way to dispel these is by separating
situations into what I call a patch (a single occurrence of a nonconformity that
involves little risk and needs not be recorded), a corrective action (a more serious
nonconformity involving some risk that requires action to prevent recurrence and
must be recorded), a preventive action (a process that can be improved to prevent
occurrence of a nonconformity and is to be documented) or a developmental action
(a planned change to introduce a new process or product in response to strategic
objectives, documented as a preventive action). Consider the examples in Table 1.
(Go to www.asq.org, and click on the cover of Quality Progress.)
Corrective Action Process
- Locate and document the root cause of the nonconformity.
- Scan the entire system to ensure no other similar nonconformity could occur.
- Analyze the effect such a nonconformity may have had on a product or service produced before the nonconformity was discovered, and take action appropriate to the severity of the situation by either recalling the product, notifying the customer, downgrading or scrapping product.
- Establish thorough follow-up to ensure the correction is effective and recurrence has been prevented.
Preventive Action Process
- Take proactive steps to ensure a potential nonconformity does not occur.
- Employ process and system analysis to determine how to build in safeguards and process changes to prevent nonconformance. For example, use a failure mode and effects analysis to identify risks and potential deficiencies and to set priorities for improvement.
Developmental Action Process (Treated as Preventive Actions)
- Initiate an improvement project, with project plans, justification for planned expenditures, resource controls and evaluation.
- Contain a related series of actions, often separated by long periods so you can wait and see progress and results.
- Use a variety of appropriate disciplines at different times during the project.
- Establish a means for communicating what has been done and what has to be done to facilitate communication about changes to project team members.
- Include a clear trail of actions taken and decisions made to substantiate the decision to proceed, document lessons learned and avoid needless reinvention on future similar projects.
Documenting and controlling corrective and preventive actions ensure appropriate action is taken within a reasonable timeframe and the resulting changes work.
- ANSI/ISO/ASQ Q9001-2000 Quality Man-agement Systems—Requirements, ANSI/ ASQ, 2001.
- Robitaille, Denise, The Corrective Action Handbook, Paton Press, 2002.
- Stamatis, D.H., Failure Mode Effect Analysis: FMEA From Theory to Execution, second edition, ASQ Quality Press, 2003.
RUSS WESTCOTT is president of R.T. Westcott & Associates, Old Saybrook, CT. He is a Fellow of ASQ and an ASQ certified quality auditor and quality manager. Westcott serves on several committees of ASQ’s Quality Management Division and is a certified quality manager refresher course instructor. He is co-editor of several Quality Press books, including The Certified Quality Manager Handbook and The Quality Improvement Handbook, and author of Simplified Project Management for Quality Professionals.