This is the nightmare scenario for most of us product designers. The cost of testing was already high, but re-testing will stretch the planned budget and slow down the entire project.
The misplaced confidence that has led to a failed compliance test, means that design engineers need to find out why the product failed and how to fix it.
To avoid this scenario, pre-compliance testing should not be considered as an add-on to the end of a project. Instead compliance testing should be built into a project from day one. In the software testing industry, there is a move to shift testing left and introduce it earlier in the product development lifecycle. Likewise, this thinking is moving to the electronics industry - investigating emissions from your device during each major development stage is the best way to avoid costly re-testing and high failure rates.
There are a number of advantages of pre-compliance testing:
1. Early error detection speeds up project lifecycle
The earlier product deficiencies are identified in the development process, the easier it is to rectify any shortcomings. Fixing problems after compliance testing is much more expensive and time consuming than fixing them during the design stage. Pre-compliance testing can focus on the areas that you have identified as potential causes for concern and find solutions for them early.
The risk to a design failing is usually relative to how long you delay testing, so designers that leave testing to the project end are completely reliant on the design team’s skill and experience. An analogy I like to use is the process of baking a cake without checking the taste at different phases of the process, but instead throwing it all together, baking it and then finding out you forgot to add enough sugar.
Early analysis of the electronics can also drive system decisions. EMC is not just about electronics, it’s about the system and mechanical changes may be required, such as adding EMI shields, coating boxes or adding EMC foam to fill any leaks/gaps in an enclosure.