Difference between Non-Conformance, Variance and Deviation

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vw08417n

Could someone please explain the difference between deviation and variance? I am currently revising SOP's and need to make sure I am including the right information and applicable forms. I work for a medical device company for dental implants.
 

shimonv

Trusted Information Resource
Okay, I can start.

Variance is not a term I would use in a QA procedure. For me, this term can be used to differentiate different configuration of the same device. For example, you can have a basic model or one with added memory or wi-fi capability (optional models).

nonconformance according to 21 CFR 820.3(q) is:
"Nonconformity means the nonfulfillment of a specified requirement."
For example, if the device you built in production does not mean the predefined spec then you have nonconforming product.

Deviation is a rare situation where you approve a deviation from the QMS processes for a limited time period, with the proper justification. It usually results from Operations constraints. For example, if there is a minor issue with production and there is already a solution on the way but it won't be available before two weeks and you don't want to stop production - you can do a deviation.
As I wrote, it's not a recommended practice but it happens.

-Shimon
 

Ronen E

Problem Solver
Moderator
Could someone please explain the difference between deviation and variance? I am currently revising SOP's and need to make sure I am including the right information and applicable forms. I work for a medical device company for dental implants.

Basically they all mean the same - a situation where the actual is not the same as the requirement / specification. The terminology used changes as you move among fields (ie medical devices, pharma etc.) and companies. In my experience "non-compliance" is the most prevalent, especially in issued regulations and standards. I've seen "deviation" used a lot in the pharma industry, and "variance" too albeit to a lesser extent.

I think almost everyone uses "non-conformance" (or "non-conformity") in the same meaning, to denote a product or a situation which is unintentionally not at par with the requirement. "Deviation" is sometimes used in the same meaning, and sometimes denotes a planned detour from specifications, eg to validate experimental / alternative process settings. I once worked for a company that used "deviation" and "planned deviation" to distinguish between those two situations. In some places "variance" is used in the "planned deviation" sense, but sometimes it simply means a NC.
 
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Duke Okes

Although they are similar, in certain industries they have very specific meanings. Pharma, medical devices,...

Might want to peruse GMPs.
 

Al Rosen

Leader
Super Moderator
Ref EIA649
variance
A departure from approved product definition
information, for a limited amount of time or for a
specified effectivity, that does not require
revision of approved product definition
information.

Deviation is the same as variance.
 
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gutierrez

In my experience, yes non-conformance is product not conforming to specs. However, I never do "planned deviation", a deviation should not be planned but occur unexpectedly and may or may not cause a non-conformance. In other words deviating from the process still may produce a conforming product but this needs to be monitored before product is released. Also, a deviation can be applied more widely to any action that does not follow an SOP or protocol. Instead of doing a planned deviation its best to update the protocol as needed to deviate or you can make a temporary change and perform the action under that quality system. In rare instances a company may allow a memo instead of updating the whole procedure under a change control in which the memo can be removed if this is a temporary change or it can be used while processing the change.

The term deviation or CAPA, which is what is done to correct any deviations that have long term effects and prevent future deviaitons of that type. The product produced under that deviation can not be released until the deviation is resolved and if the product passes its given criteria. These are reviewed at end of year or next audit. However, a non-conformance, if major sets off more investigation and potentially product retention and recall with notification of the governing body.
 
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snoopy2017

Deviation - departure from a QMS process, planned or unplanned. Planned deviations need to be approved. Unplanned deviations, need to be documented with a possible corrective action.

Nonconformance - nonfulfillment of a requirement - could be at the inspection level, during production or upon final testing.
 

billydylan

Registered
Could someone please explain the difference between deviation and variance? I am currently revising SOP's and need to make sure I am including the right information and applicable forms. I work for a medical device company for dental implants.
The definitions from others are mostly accurate. But my experience is that a rigid treatment of nonconformity/deviation is unrealistic. There are countless scenarios where a very minor, non-impacting distinction in a component could make it fail spec. No one is talking about compramising on the things that matter, on real safety or real efficacy. But I've seen suppliers provide labels that are slightly the wrong color. Additionally some suppliers will request a deviation in addition to their own non-conformance as a way of protecting the business from eating product. We must remember that even in the non-conformance process we have the option to "accept as is" with sufficient investigation and justification. For me a deviation is usually a good sign, because it's a sign that the business stakeholders are involving quality in their problems before they get to a control point, asking quality to help them understand what is a real problem versus what is a minor cosmetic issue, etc. But, if you use them its important to help the business stakeholders understand that a deviation is not a magic wand that allows bypassing GMP, safety or efficacy. Its a tool used by Quality to collaborate with the business on problems.
 
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optomist1

A Sea of Statistics
Super Moderator
in some fields, a "Variance" is synonymous with "Waiver"...i.e. an "issue" discovered during or post start of production, whereas Deviation is prior to initiation of production
 
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