Testing the Testers – Round Robin Product Verification

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Testing the Testers – Round Robin Product Verification

In part 2 of the Behind TCO Certified series, we looked at how third party product testing and verification takes place. Equally important is to ensure that the third parties doing product testing are doing so using consistent test methods and producing consistent outcomes. Round Robin testing between facilities is one way TCO Development carries out this quality assurance. Here we take a closer look.

Part 1. TCO Certified Criteria – the What, How and Why

Part 3. Testing the testers – Round Robin Product Verification

Part 2. Quality assurance – Product Testing and Verification

Part 4. The science behind the certificate – the research behind the criteria

Verifying accuracy of third party testing

As we saw in Part 2 of the Behind TCO Certified series – Product Testing and Verification – third party testing and verification of compliance are cornerstones of quality assurance in TCO Certified. Verification is important not only during the certification process, but also as a continual follow up to make sure that certified products continue to meet the criteria over time. It’s also important to verify the accuracy and consistency of test results from third party testing and verification facilities.

We do this primarily in two ways:

1. ISO accreditation. We require that all facilities testing products for TCO Certified are accredited according to ISO/IEC 17025, the international standard for facilities carrying out testing and calibration. Any test house or verification body working with TCO Certified has been independently verified to comply with this ISO standard.

2. Regular “Round Robin” testing. A technical team from TCO Development visits each of our independent verification partners and supervises testing on selected TCO Certified product samples. The same product sample is used at each test facility so as to measure consistency in outcomes between the various test sites. The team checks for accuracy in how testing is conducted, as well as repeatability in test results between facilities.

Round Robin product testing helps ensure that all our test and verification facilities are producing accurate, repeatable results, regardless of their location 

Ensuring this consistency in testing is important for monitoring that certified product models live up to the criteria in TCO Certified as well as buyer expectations for a sustainably designed and manufactured product. Here we will take a closer look at the Round Robin testing process.
A. The Round Robin Process
We select a sample TCO Certified product. Typically this product sample has some extra design features, therefore challenging the test team in all aspects of the criteria.

Steps 1-5. Product sample is tested and verified in succession at each accredited testing and verification facility (example shown here –facilities A-E)

Step 6. Product sample goes through a repeat-test round at first test site (Facility A)


TCO Certified - Round Robin Testing
B. Follow-up Process
Following the product test rounds, all test data is analyzed for accuracy and repeatability across all facilities.  Each site should produce the same results when working correctly with test measurements and equipment calibration. As a follow up, any necessary corrections or adjustments in test routines are made directly with the relevant facility.
Typically the Round Robin process is carried out every two years. The test round portion takes between two-three weeks, with the data analysis portion directly following. Regular dialog with verification partners as well as product spot checks are an ongoing process in addition to Round Robin testing.

Some common questions about Round Robin testing

Martin Söderberg , Regional Manager, Asia at TCO Development explains more about the Round Robin process:

MS – As TCO Certified is a third party certification, credibility is important. With certified products found all over the world, it’s important that a certified product found in Japan for example, offers the same sustainability attributes as the same model sold in Brazil, Germany or the United States. Products are tested in a number of different facilities, so we need to make sure that the process is carried out consistently and accurately. Buyers put their trust in TCO Certified and want to feel confident that the IT products they choose meet sustainability criteria in all phases of the product life cycle.
MS – Typically at least every two years. We also maintain a regular, open dialog with all our independent verification partners, meeting yearly to discuss open issues, test methods and criteria.
MS – We work with a number of verification partners around the world. They represent the world’s leading testing and quality assurance organizations and are located in countries where certified products are most commonly made; – China, Taiwan, Japan, Korea for example. We also have verification partners in Germany and Sweden and work closely with locally-based experts in factory auditing and socially responsible manufacturing.
MS – The TCO Development team purchases a certified product model and we take this sample to each of our verification partner sites, where a TCO Certified test is simulated on the sample. We try to choose a product with some extra design features so that we can challenge all aspects of the test protocol. For example our most recent sample was a display with automatic brightness sensor and a height adjustable stand. The test engineers worked hard to achieve the correct product settings in order to carry out the testing correctly.

Testing is overseen by our team, results recorded and the verification partners are advised of any corrections that are needed in measurement methods, equipment calibration or interpretation of the criteria. The same process is carried out at each facility with the same product sample, which allows us to compare results between sites and identify any inconsistencies. A final test round is performed at the same facility that did the first test. That way we can make sure that the performance of the sample has not deviated during the round robin process. The goal is to make sure that, regardless of the location, each test site is producing repeatable, consistent outcomes. The test portion of a round robin takes about two weeks, but the entire process can take up to six months, as we work individually with each lab to implement any necessary updates and changes. It’s of course an important process from a quality standpoint and also helpful for our verification partners.

MS– Thankfully major inconsistencies are rare. We work with each facility to make sure any deviations are immediately corrected and provide additional training to prevent any further problems. Re-testing will take place if needed. In any cases of continued inconsistencies or failure to address identified problems, we do have the option of cancelling a facility’s eligibility to test for TCO Certified.

Manufacturers – Interested in certifying your products?

A first step to certifying your products is to review the relevant product-specific criteria document and then send a product sample to an independent verification partner. For help with this, contact us or

Find a verification partner
Want to learn more?
2017-03-06T09:59:15+00:00 9 March, 2015|Categories: News|Tags: , , |