When approaching testing something there needs to be an up front decision on how proactive and how reactive you want to be. Being fully reactive is ok for a simple product, but as soon as complexity rises you will pretty quickly crash and burn. Being fully proactive is important for a complex product where failure has a high cost, but for a simpler product will mean entering a maintenance hell from which it’s hard to return. I like to think about achieving the right balance, where a small amount of maintenance is required to keep us at an acceptable level of risk of failure. This is the test orbit.
the testing graph 