ISO/IEC 17025 clause 7.7.2: use proficiency testing and comparisons
Clause 7.7.2 requires performance monitoring through comparison with other laboratories where available and appropriate. This planned and reviewed monitoring can include proficiency testing, other interlaboratory comparisons or both. Participation should provide technically relevant evidence, not merely a certificate for the assessment file.
What clause 7.7.2 requires in practice
Clause 7.7.2 adds an outside view to the laboratory's monitoring. Where other laboratories are available for comparison and it is appropriate, the laboratory monitors its performance against them. This is planned and reviewed, and it can draw on one or both of two routes: taking part in proficiency testing, and taking part in comparisons between laboratories that fall outside proficiency testing.
The standard notes that a proficiency testing provider which meets ISO/IEC 17043 is regarded as competent for that role. It does not prescribe how often or for which methods, and the words available and appropriate mean the laboratory must make a reasoned judgement and be able to explain it. Results are then analysed and used under the general rules for monitoring data, with action where they fall outside criteria. Accreditation bodies often add their own participation policies, which the laboratory needs to know.
Distinguish the comparison types
Proficiency testing evaluates participant performance against predetermined criteria through an interlaboratory comparison. Other comparisons may serve useful purposes without meeting that description. Describe the activity accurately and assess whether its design, material, method range and evaluation are suitable for the laboratory's work.
The standard identifies providers meeting ISO/IEC 17043 as competent proficiency-testing providers. Check the relevant provider evidence and any accreditation-body policies applicable to your participation. Do not assume that a familiar provider name makes every available scheme appropriate for your scope.
Plan coverage and review
Consider the range of laboratory activities and where external comparison evidence is needed. Availability can differ by technical field. Plan participation and review in a way that fits the activities and applicable recognition requirements; ISO/IEC 17025 itself does not prescribe one universal annual frequency for every test or calibration.
Where a suitable scheme is unavailable, evaluate other appropriate comparison options and discuss relevant expectations with the accreditation body. Do not interpret “where available and appropriate” as permission to make no enquiry or to rely indefinitely on a general statement that nothing exists.
Evaluate what the result demonstrates
Review the outcome, technical conditions and limitations. A satisfactory result supports confidence for the activity represented; it does not prove competence for every method, matrix, range or location. An unsatisfactory result needs a technically informed investigation and consideration of affected work.
Link the findings to clause 7.7.3 and, where relevant, nonconforming work and corrective action. Investigate causes, take appropriate action and check effectiveness. Re-entering a scheme until a satisfactory outcome appears does not by itself demonstrate that the underlying weakness was addressed.
Why clause 7.7.2 matters to the laboratory
Internal checks can agree with each other and still be wrong in the same direction. Comparing with other laboratories is one of the few ways to discover a shared bias, a misunderstanding of a method or a systematic problem with a reference. Customers and accreditation bodies place weight on external evidence because it is independent of the laboratory's own opinion of itself. Handled well, a comparison tells the laboratory where it stands and where to improve; handled as an annual formality, it produces certificates and little learning. Laboratories with limited schemes available gain by documenting how they looked for alternatives, since that shows judgement and not avoidance.
How to implement clause 7.7.2
Plan external comparison as part of the scope, with named owners. Keep records of schemes considered but not used, with reasons, so that gaps in coverage are visible, justified and reviewed again at the next planning round.
- Make a list of the laboratory's activities and mark which ones have a suitable scheme or comparison route.
- Check each scheme's design against the range, matrix and method used, and the provider's evidence of competence.
- Confirm what the relevant accreditation body expects for participation in each technical field.
- Where no scheme exists, set up or join an alternative comparison with defined criteria and record how the options were explored.
- Assign someone technical to review each outcome with the people who did the work, not only an administrator.
- For unsatisfactory or questionable results, investigate causes, look at affected work, act and check that the action worked.
- Update the plan each cycle to widen coverage and to reflect new services.
Two illustrative external comparisons
A calibration laboratory selects a comparison relevant to its measurement range and evaluates the result against the scheme's criteria and its uncertainty claim. It avoids using participation in an unrelated range as evidence for a new service that has not been meaningfully examined.
A specialist materials laboratory cannot identify a suitable routine proficiency-testing scheme for one activity. It evaluates an appropriate interlaboratory comparison, documents the technical basis and checks the recognition body's expectations. The alternative is planned and reviewed rather than arranged informally with no clear criteria.
Evidence and common mistakes
Keep the programme, suitability decisions, participation information, outcome reviews and relevant actions. A planning matrix can be useful but is not a universally prescribed format. Ensure technical personnel understand the outcome, not just the person who registers the laboratory for schemes.
Avoid treating a participation certificate as a satisfactory performance result, generalising one success to the entire scope, or investigating only the scheme's administration after an adverse outcome. Also preserve the distinction between a technical comparison and accreditation itself: a provider does not grant laboratory accreditation through a proficiency-testing report.
Frequently asked questions
Does every method require the same annual proficiency test?
The standard does not prescribe one universal frequency or identical scheme for every method. Plan suitable monitoring and meet applicable accreditation-body participation requirements.
What if a relevant proficiency-testing scheme is unavailable?
Consider appropriate alternatives such as other interlaboratory comparisons and confirm relevant recognition expectations. Document the technical basis rather than treating unavailability as an automatic exemption from review.
Does a satisfactory proficiency-testing result prove accreditation?
No. It is evidence about performance in the represented activity. Accreditation is a separate assessment and decision for a defined scope.
Turn this requirement into reliable laboratory practice
Sterling can help your laboratory organise comparison planning, outcome review and follow-up as part of accreditation preparation. Bring your scope and current participation history to a free consultation to identify meaningful evidence gaps.
Build the team's understanding through ISO/IEC 17025 Awareness. Discuss the relevant scope, employee learning and agreed access to Effivity ISO & GRC automation software with Sterling; laboratory technical decisions remain with competent, authorised personnel.
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