Having these rule of thumbs as guidelines doesn't mean that they're actually followed. :-) One thing I've seen in tech companies is they invest heavily in eng

Having these rule of thumbs as guidelines doesn't mean that they're actually followed. :-) One thing I've seen in tech companies is they invest heavily in engineering at the beginning, justifying it as a fixed cost. As the company grows, they stop growing the so called "fixed" cost, and hire more in sales, services and support. (So called "variable" costs) The reality is these salespeople sell custom deals to hit their revenue #s (especially in tough quarters) so the engineering work goes up. If staffing doesn't go up, you wind up with tremendous technical debt.