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? While 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 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, 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 already confidence that the product is sufficiently robust, storage and operational tests may be combined as a sequence, offering a reduction in time over the tests performed individually is a practical solution.

National differences

Often, manufacturers test their products repeatedly to similar but slightly different standards in order to meet country specific requirements. The CB Scheme is the world”s first international system for the mutual acceptance of test reports and certificates for electrical and electronic components, equipment and products. It does not completely eliminate the need for additional “in-country” approval or testing but does get you 85 per cent of the way there. The multilateral agreement reduces significantly the need for duplicate testing, is operational in over 50 countries, and is being used by more than 15,000 manufacturers worldwide. Many countries will now accept CB Test reports and certificates without the need for local certification. The ability to carry out one test programme to in effect gain many national marks, faster and at a lower cost surely means that more should be taking advantage of it.

Advising customers

Frequently, we find that a customer’s original requirements are flawed because of:

Poorly understood environment – while the customer is aware of the intended environment, they do not necessarily capture all of the environments for every possible use, often concentrating on operational environments and neglecting transportation.

Poorly defined test requirements – the test standards and methods that are defined by the customer show a misunderstanding and tests are incorrectly specified.

Exaggerated test parameters – there is always a temptation to be ‘safe’ with test parameters, involving rounding up and adding safety margins. Be sure that this has only happened once, not once for each person involved!

When a customer demands that certain tests are done, it is therefore advantageous to reassess if they are required, or determine if they can be reduced. Most importantly, first check that the standards relating to the product have been interpreted correctly. Also, carry out some research in order to assess what testing has already been performed, and look for similarities with other products. If you do have to test you can also save time and money by looking at how you might combine tests and reduce test durations where possible.

By making an investment in time and thought at the outset of a testing programme, and considering some of the advice outlined above, you could find that you will make significant long-term costs savings, as well as release products onto the market quicker to stay one step ahead of the competition.

Jean-Louis Evans, Managing Director at TÜV SÜD Product Service

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