Mean Time To Failure

December 06, 2004

In the computer hardware world there is a term, "Mean Time to Failure" that measures the average time a device is expected to last under normal wear and tear before failing. Of course you don't always get the mean time, sometimes you get more and sometimes you get less.

Take our toilets for example. The apartment we are renting as two bathrooms, one that gets used all the time, and a second that gets used primarily as a backup when the first is occupied. This past week the flap inside the tank on both toilets stopped working properly. Both are now sticking in the up or open position causing the toilet to run on and on and on. Now I suspect that both flaps were installed at the same time, and while our usage has been lopsided in favor of one, you could probably make a case for each flap having roughly the same wear thus far in its lifetime. But what are the odds that both flaps would stop working in the same manner within days of each other?

That's a pretty tight mean time to failure.

All of this gets me to thinking the people have a mean time to failure too, physically, emotionally, and mentally. The general reduction of difficulty getting food and shelter has lengthened our lifetimes considerably in the past century or so. More people are living longer, more people are active and working longer than ever before. The ultimate mean time to failure is our lifespan. Men generally get to the mid-seventies and women a few years more. Of course the lifetime you lead will cause your mileage to vary. The past year with all of its stress must have shortened my time. We've been way beyond normal wear and tear for some time now.

My only question then is this: will I be aware of my own flap getting stuck or will that failure be it?

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Mark H. Nichols

I am a husband, cellist, code prole, nerd, technologist, and all around good guy living and working in fly-over country. You should follow me on Twitter.