Proficiency Testing (PT) Schemes and QA systems

Participation to proficiency tests (laboratory evaluating interlaboratory tests) is considered mandatory for laboratories accredited according to ISO/IEC 17025 and EN 45003. Checking analyses results with those of other laboratories is an important third line quality control element. Corrective actions may be taken if the results deviate systematically.

If a laboratory participates in PT evaluations, clients of the laboratory find a better guarantee that the results remain their integrity when the sample is tested again by other laboratories.

"Proficiency Testing is the use of interlaboratory study to determine the performance of individual laboratories for specific tests and to monitor laboratories' continuing performance. Participating in PT-schemes provides laboratories with an objective means of assessing and demonstrating the reliability of the data they are producing" (quoted from ISO Guide 43)

Confidence that a laboratory consistently produces reliable results is of major importance to the laboratory itself and the organization it belongs to. Also (potential) customers and accreditation or regulatory bodies are very interested.




The special advantages of PT-schemes organized by iis

  • iis participants are allowed to use their own methods of analysis
  • iis reports back in two months
  • iis programs are truly global
  • iis participants truly represent all industries
  • iis maintains an ISO/IEC 17043 quality system
  • iis tariffs are moderate
  • iis reports comment on results, methodologies, trends
  • iis treats all data highly confidential





A typical PT-scheme report

The Institute for Interlaboratory Studies writes a comprehensive report for each study. Many participants have interest in the background of the samples, the statistical details, the detailed results and comments on the test results. The reports also contain a summary for executives.

The iis reports can be obtained. Please send us an e-mail and the requested report will be sent to you by returned post.

IMPORTANT !! In the report the test results, the performances (z-scores), the test methods and all other confidentional information is presented under Labcode. The relation between Labcode and participant is only revealed to the laboratory itself.




This year's program.

The iis yearly program starts in August and proceeds to July next year. During the summer holiday periods the program is on hold.




Specially developed PT-schemes tailored to your requirements

If you need a PT-scheme, for instance for evaluation of supplier laboratories, laboratories of your group or similar laboratories in your own region, iis will be happy to organize such a tailor made scheme.

The schemes are set up to the wishes of the client, but the set-up will always be based on international accepted protocols like ISO 5727, ASTM E691, IUPAC, JAOAC, DIN 38402 or NEN 6303. A broad range of samples and sample types can be handled. The tailor made interlaboratory studies may be on petroleum products or petrochemicals, but also other type of products, like soils, foodstuffs or gases.




New Schemes and ideas

To meet the whishes of its clients, the Institute for Interlaboratory Studies is continuously expanding the PT-schemes it offers.


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