An aerospace company gets a big military contract to produce a new fighter aircraft. During the design process it was realized that aircraft weight issues were going to be a major ongoing issue, so they appointed a manager to track weight across all of the engineering groups so that problems could be detected and corrected early. The newly appointed manager checks in with all of the group managers and collects current estimates and trend data. Eventually, he gets to the Avionics Software group and asks for their weight data.

"Um. Zero."

"What? Aren't you putting software onto the fighter?"

"Yes"

"Well, how much will it weigh?"

"Zero."

Exasperated, the Weight Manager points to a deck of punch cards on the desk.

"There... That's software, right?"

"Yes..."

"How much do the cards weigh?"

"Ahh. You don't understand. We only use the holes."

-- Charles