Test & Measurement
Beware of over testing
Erring on the side of caution many manufacturers tend to over test their products. According to Jean-Louis Evans, however, there are many advantages for those companies that re-consider their approach to testing – are the tests strictly necessary or are they being duplicated elsewhere?
W
hile testing both end products and their components is critical, this can often be duplicated unnecessarily to ‘cover all bases’. This reflects a poor understanding of the intended environment and of the specifications used to determine if testing should be done. Consequently, most designers and manufacturers err on the side of caution and often over test their products. Protecting a brand’s reputation is a key
reason for ‘over testing’. This is because brand loyalty can be lost quickly if a product is defective, unreliable, or, in the worst case scenario, injures someone. The cost of post-sale warranty returns is also another key driver for ensuring that the correct tests are done to help reduce product failures. The importance placed on warranty returns is reflected in the fact that many serious complaints are usually handled at a high level within a business. The warranty issue is linked closely with customer satisfaction. It’s obvious that customers will have more confidence and faith in their suppliers if they can prove that they have an effective test strategy in place. Being able to demonstrate to customers that you are a diligent supplier, even if they do not require it contractually, will inevitably give them greater confidence. Another issue that drives a company’s
12 April 2012
approach to product testing is its overall policy, which is potentially linked to a bad experience in the past that had a significantly negative impact on the issues of brand, warranty and customer satisfaction. If a company has experienced this, it may be over cautious in terms of the amount of testing done in order to try and ensure that products never fail again.
Testing blind spot While there are of course good reasons for testing, these often lead to a blind spot in terms of unnecessary over testing, which means that there are many considerations that should first be taken into account before embarking on a set of expensive tests.
There are a huge variety of tests and
standards that have very similar specifications. So, it is important to check whether the product in question has been tested to another specification. If it has, a ‘read across’ approach may be appropriate. This is where test specialists compare two standards, identify where they differ and create an argument for partial testing or no testing at all. It’s also vital to consider if the product in question is very similar to others that have already been tested, as a qualification by similarity may also be possible. Once again,
Components in Electronics
it may be possible to ‘read across’ from the previous product’s test results to avoid some re-testing. This often applies to product upgrades where it is the same product but with some additions. Likewise for a full product range, it may be possible simply to test the basic and top- end product without testing all of the model variations in between. Even if a product is vastly different from
a previous model, there may be constructional similarities which could reduce the requirement for embarking on specific tests such as contamination. For example, when the materials used are the same as those on previous products, there will be no need to run the very specific requirements of contamination testing again. Likewise, if the material’s performance characteristics are already known and are intrinsically resistant to the known contaminants and their conformance can be proven, there may
also be no reason to test. An example would be that we know that plastics do not rust when they get wet. If it transpires that your product does
require testing, very often the duration of tests can be cut to reduce costs. Historically climatic tests were run overnight starting at 5PM and ending at 9AM, so a 16 hour dwell time soon became the standard. If a product stabilises more quickly why would you pay for unnecessary laboratory time? Stabilisation time plus of two hours is now accepted and is the common sense approach unless the sample is large or bulky.
It is also important to consider if combined tests satisfy two requirements. For example, an altitude test may satisfy both an altitude and a temperature requirement, thus significantly reducing test times and laboratory costs. Where there is
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Jean-Louis Evans
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