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Miriam Boudreaux  |  10/05/2009

Miriam Boudreaux’s picture

Bio

Appropriate Handling of Out-of-Calibration Equipment

Calibration data are the key to preventing and handling out-of-calibration equipment.

If you have ever found equipment that is out of calibration, then you know it is not something to take lightly. Whether you manufacture children’s toys or automobile tires, you know that the implications and ramifications of the decisions you make can be devastating for your company. Although the requirements from the ISO 9001 standard regarding equipment found to be out of calibration are simple and succinct, this is not something to take for granted. If you ensure that the processes for handling nonconforming equipment are in place and if you take into consideration the steps provided below, you will be ready to handle and perhaps avoid out-of-calibration conditions.

Equipment found out of tolerance

When calibrating your equipment and finding it to be out of tolerance, ISO 9001 requires you to consider the product that was inspected with such equipment as suspect product. Aside from quarantining the equipment for further adjustments and calibration, the first question you need to ask is: Does the calibration data suggest the equipment was broken, minimally out of tolerance, or grossly out of tolerance? Was it out of tolerance in the range in which it was used?

Review the calibration data in detail so that you can assess your confidence that the product that was inspected on this equipment is meeting specifications.

Your next questions are:

• How much product was inspected or tested using that equipment?

• How much product that passed inspection was sent to inventory or was shipped to the customer?

If you don’t have confidence that the out-of-tolerance equipment was capable of producing good results, then you must handle the suspect product as necessary, including segregation, quarantine, recall, reinspection or retesting (using recalibrated and approved in-tolerence equipment), and repair or rework the product. Some steps to take are listed below:

• Product that has not been shipped needs to be segregated immediately for subsequent inspection or testing.

• Product that is in the warehouse has to be pulled and retested or reinspected.

• If the product has already been shipped, the standard requires that you have a process in place for how you are going to recall it. If it was already delivered to the customer, the question is: How you are going to ask for the product back to inspect or test it again?

Perhaps if the customer uses your product as raw material and they have not used it yet, you may be able to go to their facility and conduct the inspection and testing there. If that is not possible, due to equipment and the setup you have in-house, then proceed with your recall process and conduct the reinspection or retest at your facility.

 

In all cases, you need to have a plan of action in place if the results of the reinspection or retesting of suspect product are unfavorable. Is it possible to repair or rework the product, or must it be scrapped and replaced?

The handling of equipment that is out of calibration must be a well-planned, documented process, preferably using the same control-of-nonconformance procedure already required by the ISO 9001 standard.

Preventive steps: importance of the data in the report

Too often when equipment is outsourced for calibration, you receive a calibration certificate that doesn't have the calibration data. This does not seem to be a problem until the equipment is found to be out-of-calibration. Having the calibration data is important in these occasions, because it gives you a chance to review the data and perhaps draw some conclusions as to why the equipment  is out of calibration. By the way, the following items to check are not only important to review when an instrument is found to be out of calibration but should be looked at frequently in order to get a feel for the characteristics of this instrument and how it was calibrated. Look for the following items in the calibration data:

  • Is it being calibrated at the correct range or ranges?
  • Was it found to be marginally out of calibration or grossly out?
  • Was it in good shape and within specification every time it was calibrated?
  • Can it go longer between calibrations?
  • Does it go a shorter time between calibrations?

 

For example, if you calibrate a certain piece of equipment every six months, and every six months when you get the results, the equipment is in perfect tolerance, you may decide to increase the calibration cycle to every year based on these results. Perhaps not immediately but after three or four cycles of calibration, you can safely increase your time between calibration for the specific equipment. However even when you go to a one-year cycle, you will want to keep reviewing your calibration records to see if the equipment is always received by the calibration lab in tolerance, and if so, ensure the data is clearly confirming that.

As you continue to review your data, you may decide that a one-year calibration cycle is good, but perhaps you might want to increase it to even a greater span, such as every one-and-a-half years. You don’t, however, want to push the equipment to the limit. We are talking about being economical but still having the confidence that the product being inspected or tested meets specifications.

In some cases, when equipment is used extremely infrequently, it may be necessary to calibrate before use, rather than keep the equipment in a calibration cycle. However, appropriate labeling and planning will be necessary to ensure that equipment is ready to use when needed.

What to report on the calibration certificate

You—not the calibration technician or outsourcing company—need to decide what you want to see on your calibration report. If you plan well, then you will always have all the information available should discrepancies or out-of-tolerance conditions occur.

Here are some of the most important fields:

• Description of the equipment, equipment ID

• Location of the equipment. Who the owner is and if the equipment is assigned to certain employees.

• Calibration date and next due calibration date

• “As found” condition. This is very important and is essential for detecting if the equipment was found out of calibration or not. The idea is that when you first take the equipment in for calibration, you record whether the equipment was found in tolerance or out of tolerance.

• Calibration readings or the data. Sometimes calibration reports only contain the “as found” condition and state that the equipment was brought to tolerance, or is in calibration, but you don’t know if the equipment readings were marginal or if the equipment readings were actually out in several points of the range.

• Standard used to calibrate your equipment. The standard name, ID, description, the last calibration date and the next due calibration, and whether the standard is traceable to national (such as NIST) or international measurement standards.

• The name of the person conducting the calibration

• The procedure or method used

 

If you address these simple steps in your calibration process and management system procedures, then you will be prepared should any of your measuring and test equipment be found out of tolerance.

Discuss

About The Author

Miriam Boudreaux’s picture

Miriam Boudreaux

Miriam Boudreaux is the president of Mireaux Management Solutions, a consulting and technology firm headquartered in Houston, Texas, providing ISO and API consulting, ISO and API training, internal auditing services, and implementation of the Web QMS hosted software platform. Miriam holds bachelor’s and master’s degrees in Industrial Engineering. She is an RABQSA certified QMS and ISMS auditor, ASQ Certified Quality Engineer (CQE), and a Certified Quality Manager (CQM). She has served as an examiner with the Texas Award for Performance Excellence and participates as a speaker at various conferences throughout the year.

Comments

Broken equipment

I was wondering if you could share your take on broken or damaged equipment. For instance, you are 4 months into a 12 month cal cycle of an electrical meter and the inspector drops it and breaks it, maybe your 10 months in.  Regardless, for the sake of this discussion lets pretend that the inspector was dilligent and honest and submitted a written account of the occurance when it happened.  Maybe e-mailed quality or used an internal form, whatever the process is.  The bottom line is you have a clear record of when and how it occured.

In my view you should use the nonconformane process to document the removal of the asset from your system and the replacement if necessary but then you are left with a situation where you cannot validate previouse measurements through As-Found data at the closure of the calibration cycle.  

I work for a calibration company so every measurment is clearly documented and I have the ability to look for trends in data suggesting it may have been producing false readings.  I can look at the history of the instrument and see if there are accounts of as found failing conditions or reason to believe that it would have been out of tolerance.  To me, that is the deviation from program, failing to compete as calibration cycle.  I've worked for a few different companies, and they all seem to have an approach to this matter however no one has ever really stated their method was based on any kind of official guidance beyond an internal procedure.

It doesn't seem realistic to take a guilty until proven innocent approach so to speak but on the other hand there should be some level of confidence the instrument was believed to be accurate during its usage.  In my case the last time the instrument was used it might have been thousands of miles away or in a different country even so I find myself searching for a cost effective approach to resolution without physical validation, or a process defending that physical validation was not deemed necessary.  

I look forward to your reply,

Jason

Broken equipment

Hi Jason, Thanks for reading the article. I will attempt to answer the best way possible:

Actually what standard suggest is that you take action when the equipment "as received condition" during calibration was found out of tolerance. Reason being as you stated is to see how much product may have been inspected when the instrument was out-of-tolerance. So on you first sentence "you are 4 months into a 12 month cal cycle of an electrical meter and the inspector drops it and breaks it, maybe your 10 months in. Regardless, for the sake of this discussion lets pretend that the inspector was dilligent and honest and submitted a written account of the occurance when it happened. Maybe e-mailed quality or used an internal form, whatever the process is. The bottom line is you have a clear record of when and how it occurred". In my opinion, there was nothing to do except to change the status of your equipment on your Calibration log or register from "active" to "inactive" or "broken/retired".

You are correct in that nonconformance process should be invoke only when have suspicion that good product may have been inspected with out-of-tolerance equipment.  In your case, as you well stated "In my view you should use the nonconformane process to document the removal of the asset from your system and the replacement if necessary but then you are left with a situation where you cannot validate previouse measurements through As-Found data at the closure of the calibration cycle" that was not necessary, because there was never a doubt that product was inspected with this broken equipment.

 

Then you go on saying "I work for a calibration company so every measurment is clearly documented and I have the ability to look for trends in data suggesting it may have been producing false readings. I can look at the history of the instrument and see if there are accounts of as found failing conditions or reason to believe that it would have been out of tolerance. To me, that is the deviation from program, failing to compete as calibration cycle. I've worked for a few different companies, and they all seem to have an approach to this matter however no one has ever really stated their method was based on any kind of official guidance beyond an internal procedure."  Again, to me, there was no need to document, prove or trend anything.  the equipment broke, is now retired and future checks will be done using a new equipment.  But when the equipment was used to inspect product, it was indeed working fine.

Finally: "It doesn't seem realistic to take a guilty until proven innocent approach so to speak but on the other hand there should be some level of confidence the instrument was believed to be accurate during its usage. In my case the last time the instrument was used it might have been thousands of miles away or in a different country even so I find myself searching for a cost effective approach to resolution without physical validation, or a process defending that physical validation was not deemed necessary". I totally agree with you.  There is no need to prove anything. I will think any auditor asking you to document through a nonconformance that the equipment broke, is not valid, required nor value add. Only if you would have found the equipment broken, without knowledge of when it broke, then I would think that it may have some merit.  However if the equipment is broken to the point that it cannot be used for its primary functions- and there is no way that it would have been used for measuring- then, again, I would not document it status through a nonconformance. 

 

Hope this helps, if not just email back.

Miriam

Product Disposition

Miriam,

Your article is outstanding, but I disagree with some subtleties. I don't know what the current wording in ISO 9001 is, but as I recall the 1994 version said that it was necessary to analyze the degree and kind of calibration nonconformance, impact on past product acceptance, and whether product disposition was required. You are implying that a recall or reinpsection is mandatory:

PP "• If the product has already been shipped, the standard requires that you have a process in place for how you are going to recall it. If it was already delivered to the customer, the question is: How you are going to ask for the product back to inspect or test it again?"

PP I think the analysis has to be done carefully and ethically and the product disposition plan executed well - be it a full recall or no action at all. A company that goes beyond the binary mentality of inspection and truly controls its processes will probably not face this calibration scenario, but if they do they will likely have (a) processes that conform to standards regardless of inspection issues and (b) the knowledge required to (hopefully) arrive at the conclusion that the product is fine despite the calibration nonconformance. For instance, if one knew that a process was incapable of producing nonconformances (perhaps limited to the range of the equipment nonconformance), no action other than reporting would be necessary. Examples would be use of robust design practices like design for assembly, classification of characteristics, failsafing, consideration of the out-of-tolerance range on the gaging vs. the range at which the product inspection was done (forgive me if you already mentioned that).

PP Also, 10 years ago I found the QS-9000 MSA manual to be an excellent guide to running a strong measurement system, as it describes ways to assess gage capabilities that are overlooked by ISO 9001. I imagine the current version is even stronger.

Product disposition

Hi Dave. Thanks for reading the article. You are correct in that recall or inspection is not mandatory. I did pose the question of assessing the confidence level in the equipment and subsequent results, but I can see the that the actions I suggested leaned towards the assumption that the monitoring or test activities using the equipment had an impact on product acceptance. Thanks for your in depth comments.

you can also analyze the data on previous equipment checks

you can also analyze the data on previous equipment checks