There
is often confusion between Product Testing in a laboratory compared with
testing carried out during an inspection. While both have a common objective to
ensure the conformity of goods, they approach that task from different
perspectives and require particular expertise.
General definition
• Laboratory
(lab) testing ensures that goods conform to the national regulations of the
country of importation.
• A product inspection ensures that goods conform to the client’s requirements, product specification, and the requested quality level. The process consists of visual checks in addition to basic product testing, also called on-site testing.
Product testing during an inspection vs. lab testing: 5 differences
1- Product Testing Environment
Laboratories
perform tests in a controlled environment under conditions defined by the
applicable standard. Testing equipment is regularly calibrated to ensure the
most precise and reliable result. The testing laboratory will ensure they
perform the analysis under the required conditions and can then certify the
compliance of the product with the standards.
Basic conditions
As most of the
testing equipment is large and heavy, quality inspectors will only perform some
of the tests if the necessary equipment is available at the factory. They will
verify the latest calibration date to evaluate the reliability of the result.
Nevertheless, the test is usually performed under basic
conditions which may not
meet all those required by the standards. For example, when the humidity or
temperature is high in the testing room, the result of a moisture test varies.
Therefore, the result of this test during a product inspection can only be used
as a reference. It cannot be used to certify conformity to standards because of
the uncontrolled environment.
2- Product Testing Purpose: Legal Compliance vs. Customer Quality
Lab testing verifies the safety of a
product or compliance with applicable standards and regulatory requirements in
the country of destination of the goods. However, just because the goods meet
the requirements of mandated tests, it doesn’t mean they are suitable for end
consumers. Compliance is but one part of Quality when it comes to what
consumers expect.
Your requirements
Product inspection assesses the quality of the
manufactured goods based on the client’s requirements which reflect the end
user’s expectations of the product. The process can’t necessarily ensure
compliance with standards, but it does guarantee that products meet
specifications deemed important to the end consumer.
3- Product Sampling
Few pieces
Due to the
expense and often destructive nature of the tests, far fewer samples undergo
laboratory testing compared with the number examined during an inspection.
Tens or hundreds
For product
inspection, quality inspectors use International standard ISO 2859-1 standard (commonly called AQL tables)
to determine the number of samples for examination. For large lots, they may
need to test hundreds of samples. For example, for an order of 10,000
Floor tiles to be exported to Europe, a laboratory needs 6 samples to verify
compliance with EN 144 and ISO 1054-5. When a quality inspector performs a
pre-shipment inspection for the same order, he checks 200 pieces (based on the
General Inspection level II) and tests between 5 to 200 products depending on
the complexity of the tests.
4 – Product Testing Frequency
Once or twice during the product life cycle
Lab testing is usually only done once, at
the beginning of a new project, and then maybe once during production. The
initial tests ensure the supplier has the capability to comply with the
standards. The second test verifies the materials,
product design, and final product comply with relevant standards when they
are manufactured on a larger scale. Most
companies don’t usually order lab tests for repeat orders as they assume the
supplier will use the same material and repeat the design as per the first lot.
Product inspections should be performed every
time a new batch is manufactured, and preferably at different stages of the
production process. Even if the design and the materials used for the
manufacturing of the goods remain the same, and the product is initially
compliant with specific standards,
it does not mean the quality will continue to be consistent over time or that
you won’t suffer any production delay. Regular inspections are necessary to
ensure the product quality continues to meet consumer expectations, and to avoid
supply chain disruption.
5. Time Required for Product Testing
Lab testing always takes longer than a product
inspection.
Results aren’t
available as soon as those from the product inspection for the following
reasons:
• Tests are
usually more detailed and analyse every component and material used to
manufacture the product, including Nano coating, calibration,etc.
• The tests are
more complicated and take longer (it may involve some chemical manipulations,
or require a test to be repeated over several hours or days)
• Independent 3rd parties in charge of
the product testing are usually off site. The quality inspector is responsible for
sending randomly selected production
samples to them.
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