Put Elon Musk's rule through your numbers

One rule JMM has located in a dated source, rebuilt as a working calculator, and taken a position on.

Sources located: TED (official talk transcript)
Source years: 2013
JMM verdicts: depends on you

Portrait: Gage Skidmore, CC BY-SA 4.0, via Wikimedia Commons. Self-hosted by JMM.

First-principles cost model

What does a product cost when you rebuild it from components?

depends on you A real method with a real survivorship problem. You are hearing from the teardowns that worked. TED (official talk transcript), 2013Open model

Not every rule here survives its own arithmetic

JMM does not grade this rule as a set. The verdict on first-principles cost model is where the position turns critical: A real method with a real survivorship problem. You are hearing from the teardowns that worked.

Each page separates three things people usually run together: what the source states, what JMM's model adds to make it computable, and where the rule itself breaks. The last one is not the calculator's limitations list. It is the failure of the idea, which is the part the person who published the rule has no reason to write down.