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BASICS
Corrective vs. Preventive Action
by Russ Westcott
Q
uality professionals frequently mented as a preventive action). so you can wait and see progress
express confusion as to the dif- Consider the examples in Table 1. (Go and results.
ference between corrective and to www.asq.org, and click on the • Use a variety of appropriate dis-
preventive action. A corrective action cover of Quality Progress.) ciplines at different times during
deals with a nonconformity that has the project.
occurred, and a preventive action Corrective Action Process • Establish a means for communi-
addresses the potential for a noncon- • Locate and document the root cating what has been done and
formity to occur. Many ISO 9000 regis- cause of the nonconformity. what has to be done to facilitate
trar auditors tell their clients to use communication about changes to
separate procedures and forms to doc- project team members.
ument each type of action. Nothing in • Include a clear trail of actions
the standard says this must be done,
Knowing the taken and decisions made to sub-
but p. 13 includes the word “prevent” difference could make stantiate the decision to proceed,
in the clauses on corrective and pre- document lessons learned and
ventive action. all the difference. avoid needless reinvention on
On closer reading, however, section future similar projects.
8.5.2 says corrective action eliminates Documenting and controlling cor-
the cause of nonconformities to prevent • Scan the entire system to ensure rective and preventive actions ensure
recurrence, and section 8.5.3 says pre- no other similar nonconformity appropriate action is taken within a
ventive action determines and elimi- could occur. reasonable timeframe and the result-
nates the causes of potential noncon- • Analyze the effect such a noncon- ing changes work.
formities … to prevent occurrence. See, formity may have had on a prod-
there is a difference! uct or service produced before the BIBLIOGRAPHY
nonconformity was discovered, ANSI/ISO/ASQ Q9001-2000 Quality Man-
Common Misconceptions and take action appropriate to the agement Systems—Requirements, ANSI/
There are three common misconcep- severity of the situation by either ASQ, 2001.
tions about corrective and preventive recalling the product, notifying Robitaille, Denise, The Corrective Action
action: the customer, downgrading or Handbook, Paton Press, 2002.
Stamatis, D.H., Failure Mode Effect Analysis:
1. The standard calls for document- scrapping product.
FMEA From Theory to Execution, second
ing every occurrence of a non- • Establish thorough follow-up to edition, ASQ Quality Press, 2003.
conformity. ensure the correction is effective
2. A preventive action is really just and recurrence has been prevented. RUSS WESTCOTT is president of R.T. Westcott
calling a corrective action some- & Associates, Old Saybrook, CT. He is a Fellow
thing different. Preventive Action Process of ASQ and an ASQ certified quality auditor and
3. The major reengineering of a • Take proactive steps to ensure a quality manager. Westcott serves on several com-
process, product or service, or the potential nonconformity does not mittees of ASQ’s Quality Management Division
introduction of a new process or occur. and is a certified quality manager refresher course
equipment, is not a candidate for • Employ process and system analy- instructor. He is co-editor of several Quality
preventive action documentation. sis to determine how to build in Press books, including The Certified Quality
Manager Handbook and The Quality
One way to dispel these is by sepa- safeguards and process changes to
Improvement Handbook, and author of
rating situations into what I call a prevent nonconformance. For Simplified Project Management for Quality
patch (a single occurrence of a noncon- example, use a failure mode and Professionals.
formity that involves little risk and effects analysis to identify risks
needs not be recorded), a corrective and potential deficiencies and to
action (a more serious nonconformity set priorities for improvement. Please
involving some risk that requires comment
action to prevent recurrence and must Developmental Action Process
(Treated as Preventive Actions) If you would like to comment on
be recorded), a preventive action (a
this article, please post your remarks
process that can be improved to pre- • Initiate an improvement project,
on the Quality Progress Discussion
vent occurrence of a nonconformity with project plans, justification for
and is to be documented) or a develop- planned expenditures, resource Board at www.asq.org, or e-mail
mental action (a planned change to controls and evaluation. them to editor@asq.org.
introduce a new process or product in • Contain a related series of actions,
response to strategic objectives, docu- often separated by long periods
104 I MARCH 2005 I www.asq.org

2. BACK TO
BASICS
TABLE 1 Four Types of Action
Situation Frequency Suggested action Type Comment
Final inspection Single occur- Rework, repair. Patch. May not need to
returns part to rence before record; depends on
operator to cor- shipment. magnitude of risk
rect. Corrected and frequency.
part returned to
original lot.
Item or work unus- Single occur- Scrap. Patch. May not need to
able. rence before record; depends on
shipment. magnitude of risk and
frequency.
Item or service Serious. Assign for action Corrective action.
does not meet Occurred more (and contact
customer require- than once and customer, as
ments. after shipment. appropriate):
• Find root cause.
• Correct.
• Document.
• Evaluate
effectiveness.
Situation that Nothing has Assign for action: Preventive action. May require long-
could potentially occurred, yet. • Analyze what ifs. term follow-up to
affect process, • Evaluate poten- ensure effectiveness.
product or service tial effects of
is found. failure.
• Identify solution.
• Implement
solution.
• Document.
• Evaluate
effectiveness.
Desire to improve No nonconfor- Assign project: Developmental Organizations fre-
the process, prod- mance exists, • Analyze present action. Use preven- quently forget to take
uct or service for and no poten- process. tive action system credit for this type of
reasons other than tial for one is • Reengineer with project man- breakthrough pro-
nonconformance. detected. process. agement. ject.
• Document
process.
• Evaluate effec-
tiveness of
reengineered
process.
00 I MARCH 2005 I www.asq.org QUALITY PROGRESS I MARCH 2005 I 00