Heusser's First Law Of Software Engineering

I got to use this term twice in the past couple of weeks, so I'm going to call it a real thing now. Here goes:

Heusser's First Law of Software Engineering
A conceptual model of a bunch of guesses multiplied and divided by each other is generally worth about the same as the web page it is printed on.

Of course, you're probably going to ask for an example .

UPDATE: I don't mean to be too critical. Asking your customers to evaluate and rank the importance of the software before you build it - to set a vision - to enable people to make tradeoffs that align with your vision - is a good thing. It's when you try to take these better-than-nothing guesses and make them feel like science - feel like proof.

I am especially leery when people drag out the summation symbol (it's a big capital E) from 1 to n of f(n) divided by n, using impressive looking graphics.

I look at the symbol and think "Hey, dude, why not just say the average of?" - especially when the text doesn't even bother to say "This symbol is the average of the values."

When I reach the point, I begin to suspect that the authors are preying on the math-illiterate.

Hence, Heusser's first law of software engineering.