Let's Talk About Test Plans and Procedures


Documenting your test plans and the detailed procedures for each test is extremely important for making sure that your tests are effective, your results are reproducible, and you generate information that is as useful as possible in diagnosing any failures.

Tests should be written in painfully clear language, even more so if they are going to get translated, or interpreted by non-native speakers of the language they're written in! Simplify, simplify, and avoid idioms, jokes, and flowery phrases. You can start a blog if you need room for your creative writing!

If you do notice anyone has misunderstood the document, this is feedback you should use to make it even more straightforward. Be extremely clear about every detail; for example, if your device has a display and the test fixture has a display, be explicit about where the error message should appear.

Use your judgment in deciding what should be in the test plan. It is definitely possible for test plans to get out of hand. Over time, tests tend to accumulate in test plans, whether or not they are even still valid. I once inherited a bunch of test documents about an ethernet-connected product, but the version we were selling when I arrived was wifi. There were simpler chips in the old design, and more discrete components. Also, there were a whole range of tests around working with the ports on a whole selection of ethernet switches, routers, and hubs, each known to cause problems, usually due to varying tolerances between manufacturers.

But in the Wifi world, everything has changed, and many of the old ethernet tests no longer make sense without an actual ethernet port on our device. Do you have any kind of test plan auditing to get rid of ancient tests? You should consider it. This is more important the thinner your margins are; if you have to have extra fixtures or extra factory workers to run through a lengthy test procedure, you can significantly dent a product's viability.

Products change, and although sometimes old tests are part of important institutional learning, other times they're just junk. Take a look, and get rid of a few!

Some other tests that you might want to include, or change up if your product or shipping methods have changed could include:
  • Product ME tests
    • Painted surface abrasion
    • Painted surface solvent resistance
    • Button presses, force and number of actuations
  • EE
    • ESD resistance, EMF resistance
  • Other
    • Temperature Max/Min
    • Temperature cycling
    • Infrared remote Range
    • Radio Range
    • Display brightness/legibility
  • Packaging/Shipping tests
    • Vibration table duration and intensity
    • Temperature/Humidity profile

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