How do you choose a proficiency testing provider?

This is a very difficult question to answer, especially if you have not participated in proficiency testing before. We have compiled what we think are the most important questions to ask of your proficiency testing provider. Some of these questions deal with participant convenience, while others deal with the things that are invisible to the participant, but very important to the usefulness and final outcome of the test.

We hope that these questions can help you make an informed choice of proficiency testing provider.

Questions to ask your proficiency testing provider:

Are you accredited?
HN Proficiency Testing: Yes, we are accredited. We have been accredited by A2LA since 2002. You can review our scope of accreditation.
Does my accreditation body recognize your tests?
HN Proficiency Testing: We know that our tests are recognized by A2LA, LAB, ACLASS/ANAB and Perry Johnson Laboratory Accreditation. If you are accredited by another organization, we will be happy to contact your accreditation body on your behalf to ensure that they will recognize our tests.
How much does it cost to participate?
HN Proficiency Testing: Our pricing schedule is posted on our website. However, the participation fee may be the least of the costs. If your results are found to be unsatisfactory, you can spend far more than the participation fee in corrective action cost. This is why it is important to choose a proficiency testing provider that uses knowledgeable technical advisors and has sound quality assurance processes in place to ensure that your results are not erroneously deemed unacceptable. Choosing a proficiency testing provider with knowledgeable technical advisors also gives you a better chance of being pointed in the right direction if your results really are unsatisfactory and you do need corrective action. This can significantly reduce the cost and effort of the corrective action.
Are knowledgeable technical advisors assigned to each test?
HN Proficiency Testing: Yes, we believe that one of the most important factors in designing meaningful proficiency tests is the involvement of knowledgeable technical advisors. Therefore we have a technical advisor assigned to each test on a professional consulting basis. The technical advisor is typically an assessor, who is an expert in the particular measurement discipline.
How are your technical advisors chosen?
HN Proficiency Testing: We choose our technical advisors from amongst A2LA assessors. Typically they are assessors that our technical manager (who was an A2LA lead calibration assessor for 10 years) has worked with on assessments. Our criterion is that the technical advisor shall be comfortable assessing the particular measurement discipline. The technical advisor is also responsible for choosing the reference laboratory for the test.
How are reference values determined?
HN Proficiency Testing: We choose our reference laboratories based on the recommendations from our technical advisors. In most cases the technical advisor has assessed the reference laboratory or has some other first-hand information on which to base his or her recommendation. We usually buy a calibration or test on a commercial basis from the reference laboratory. This approach allows us to choose the reference laboratory we think is the best for any given parameter.
Are your reference values backed up by accredited tests and/or calibrations?
HN Proficiency Testing: Yes, all our reference values are supported by an accredited calibration or test in accordance with A2LA's traceability policy. This is a requirement of our accreditation and fundamental for our credibility.
How do you know that your reference values are correct?
HN Proficiency Testing: At the start of a new test, nobody has any way of knowing if reference values are correct. While we take every precaution in choosing our reference laboratories, there is always the possibility that they make a mistake. We have procedures in place that are specifically designed to identify problems with the reference values or the stability of the test artifacts. We always let participants with unacceptable results know how confident we are in our reference value, e.g. how many participants have previously participated and how well did they agree with the reference values. We have sent artifacts out for a second opinion when we did not get good correlation initially. We also employ various quality control measures at the end of each testing round to determine if the reference values are reliable and the test artifact(s) has been stable during the testing round. Because these measures are based on all the participants' results, it is not available until the end of a testing round.
Is there somebody who can help me figure out what went wrong if my test results are not satisfactory?
HN Proficiency Testing: Our technical advisors are usually available to help troubleshoot unsatisfactory results. A quick initial review of the results and a suggestion for what may have gone wrong is included in the testing cost. If more elaborate investigations are warranted, e.g. to review and revise a participant's procedure or uncertainty analysis, the technical advisor will usually do this on a consulting basis at a cost.
Can I choose my own testing week?
HN Proficiency Testing: We understand that it is important to participants to be able to plan and know when to expect their test package, so we post our schedule and the availability of all of our tests on our website. When you register for a test, you can decide exactly which week you want your test. This allows you to plan ahead so you know that you have the right technicians available for the week of your test. Of course there is always the possibility that a package gets misdirected in shipping or a participant does not ship the package on time. If this happens we will contact subsequent participants as early as possible, so we can re-schedule with as little inconvenience as possible.
What is the lead time on the tests?
HN Proficiency Testing: This varies from test to test. You can always check it on our schedule. We try to keep the lead time for each test below 2 months. If this is exceeded, we usually duplicate the test package available.
How long does it take from when I send in my results until I receive my preliminary report?
HN Proficiency Testing: The preliminary report is the documentation accreditation bodies primarily look for as evidence that you have participated in proficiency testing. Most of the time we send the preliminary report as a PDF attachment to an email within 2 business days if the results are submitted on our website. Sometimes our technical manager is out of email range and it may take a little longer, up to a week. In rare cases, e.g. if there are questions about the reference values, it may take us a couple of weeks to get a second opinion before we can submit the preliminary report.
How long does it take from when I send in my results until I receive the final report for the test?
HN Proficiency Testing: In most cases our testing rounds run for 6-12 months. So if you are the first participant in a testing round, it can take that long before you receive the final report. Some tests are slow sellers and may take even longer to attract sufficient participants. In all cases, you will receive the final report by email automatically.