A Lego house metaphor for software and hardware failures
Last night, my daughter and I had just arrived in Portland to visit family. We were having BBQ with my Mom just after getting off the train. She was telling us her horror story about trying to figure out why her iPhone screen kept freezing, or why it tapping one icon would sometimes result in some different app launching. The Apple Genius had told her everything was fine with the device; it was just that computers just have limited memory, and that sometimes a phone just needed to be reset when it ran out. My mom, out of frustration and uncertainty about this unhelpful diagnosis, just decided to buy a new phone.
I looked at her in a bit of disbelief — not about her choice to buy a new phone, but that the Apple Genius had given her a “memory” metaphor to explain why her phone was freezing. Not only did this diagnosis seem wrong (something was clearly wrong with either the software or hardware), but the metaphor the Genius shared just didn’t seem to help my mom understand what might be going wrong with her phone.
When I balked at the “memory” explanation, my Mom balked back:
“Well if it’s not memory, than explain to me what’s happening! How could a phone work for a while, then just stop working, and then be fixed by restarting it?”
In my head, I was thinking about operating systems, memory fragmentation, memory leaks, defects, resource management, touchscreen firmware and a dozen other possible causes. These might be the actual causes, they were definitely not helpful explanations for someone who knows nothing about computers, software, or operating systems.
“Okay, imagine your house,” I said.
“Okay.”
“Now, imagine your house was made out of Legos.”
“Okay…”
“Now, imagine your Lego house had a magic button. When you press this magic button, all the pieces get taken apart and put back together in exactly the way they were when your house was first built. Every little brick that had been knocked out of place when you first moved it goes back to its place.”
“This is rebooting?”
“Yes! Every time that button gets pressed, everything inside your phone gets reset to where it was originally supposed to be.”
“Then how does the house stop working?”
“People live in it. We visit and break one of your Lego chairs. Your cat knocks something off the counter. Your Airbnb guests spill some juice on your lego carpet. Over time, people make mistakes, and your house slowly drifts away from its pristine original state.”
At this point, I could see the metaphor was working. (My mom loves keeping her house in order). So I continued.
“Now, how do you prevent these things from happening in your house?”
“I make rules. Like the Airbnb house manual. Take your shoes off, don’t flush feminine products down the toilet.”
“Yes! And do those rules always work?”
“No, definitely not.”
“And what do you do when they don’t?”
“I revise them, so mistakes don’t happen anymore.”
“Right. Your iPhone is the same. It has a bunch of rules, written by software developers at Apple, which govern how your phone works. Sometimes their rules aren’t so good, and so the software breaks over time.”
“Ah, that makes sense.”
“Here’s the difference though. How many bricks would you need to make your house? Tens of thousands? And how many rules? A few dozen? The iPhone’s house has tens of millions of bricks and and tens of millions of rules. Each engineer at Apple is responsible for a few thousand of bricks or rules, and if even one of their bricks is out of place or one of their rules is ineffective, the phone gets disordered.”
“Wow. It’s amazing these things work at all!”
“Yes, it is! Now we haven’t even talked about the bricks themselves. What if one of them is defective in your Lego house?”
“Like one in the foundation…”
“Right. The whole house might fall down!”
“That’d be like my touch screen being defective.”
“Exactly. So why wasn’t your iPhone working? One of the bricks might be defective. Many bricks might be defective. The bricks might work, but be put in the wrong place according to the blueprints. Or the blueprints might be wrong. Or maybe some occupant of your house knocked a brick out of place. Or maybe all of these things were wrong. Trying to figure how your iPhone’s house got disordered is a challenging mystery.”
“So how does anyone ever figure out what’s wrong?”
“Sometimes they don’t.”
“So what do you do then?”
“You buy a new phone.”
