The Real Software Crisis


Steve Simmons

No, it's not the crisis you've been hearing about for the last 25 years. Consider:

My kitchen radio has a bug in it. My car radio has a bug in it too. In fact, my car itself has a bug in it.

Bugs in a kitchen radio? Yes. It's a simple little bug to demonstrate. First turn the radio on, then set the timer. A little red light will let you know the timer is on, and the display starts counting down the time. When time is up, the clock beeps at you. Turn the timer off, and the red light stays on. So does the radio. Now turn the radio off, and set the timer again. When the timer goes off, the radio will come back on.

My car radio has a similar problem. If you are setting the time while playing the radio, the radio will change stations to 530 AM whenever the time you're setting moves from AM to PM. It only happens once a year when adjusting for Daylight Savings Time, but it's still an annoyance.

Two minor bugs in household appliances. Surely I can live with that? Maybe, maybe not.

My car has a problem. It pings unless I run it on premium unleaded gas. My mechanic, bless his little heart, is quite good. He told me that there was nothing he could do about it. OK, I didn't expect to have to pay for premium gas. But the car is otherwise just fine, so I'll live with it.

Then one day he called me up. He said he'd gotten a service bulletin on the car, and could now make it stop pinging. Seeing as how I was such a good customer, he'd even fix it free. So I came in, left the car, and when I picked it up it ran much better. Not only did the ping stop, but the acceleration was better too.

One problem. On hot days, the pollution control idiot light would come on when I decelerated. Back to the shop. He says yes, he's heard of the problem. No, there's probably nothing wrong with the pollution control system. It seems the repair job makes the light come on sometimes when nothing is wrong. He offered me a choice: ignore the light and take my chances, or put things back the way they were. "Just takes a few minutes," says he, "we have to change back to the old proms."

Say what? Yes, the pollution control system had a bug in it. And the bug fix for the ping problem introduced a new bug, causing occasional false warning lights.

All over the world there are people writing control programs for microprocessors. Some of them do good jobs, and some of them don't. The really bad jobs are so botched up that the product never works in the first place. The half-botched jobs are clearly defective, and either get recalled or bomb in the market place.

But some of them are 99% right. They either do something silly, like set the radio frequency to 530 AM, or they do something non-catastrophic like make the engine ping when you use regular gas. And we all live with those little bugs.

Every time you turn around, though, microprocessors show up in something else. VCRs, cameras, TV sets. My boss' new car has seven microprocessors and a small LAN. It's not quite perfect, though - every six months he has to disconnect his battery to force a system reboot. It's just another one of those things that, if they don't work quite right, 99% is good enough.

But the other day I had Old Dependable in for a tune-up, and was wandering around looking at the new cars. The salesman was telling me all about the wonderful new technologies they'd built in. Like the electronically controlled anti-skid braking system.

And I got nervous.

The new software crisis is coming. You can call it product liability, you can call it software reliability, you can call it whatever you please. I call it the One Percent crisis. We've gotten away with 99% right for a long, long time. But when software controls our airplanes, our elevators, our cars, and every other thing we take for granted, we can't live with just 99% any more. Because 1% can kill you.

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