First Principles

First principles thinking consists of deriving things to their fundamental proven axioms in the given arena, before reasoning up by asking which ones are relevant to the question at hand, then cross referencing conclusions based on chosen axioms and making sure conclusions don't violate any fundamental laws. https://en.m.wikipedia.org/wiki/First_principle

cf problem solving, framework

Preached by Elon Musk, but probably a better for fit battery design/pricing than for ill-structured domains like product management where you're dealing with claims more than physical laws.