As Reliable as the Sun and the Moon
What do customers want when they say they want reliability?
Maybe it is that the product will work when they need it to work.
Like your car starts in the dark parking garage after a long snowy day so you can head for home. The goal is getting home.
Like your backup hard drive has the files you just accidentally deleted. Sure the drive, cables, and software all have to work. The goal is to restore valuable files.
People use the products to accomplish something.
I use a wooden spoon to stir a stew as it simmers for dinner. I don’t think about the reliability of the spoon. When I buy a spoon I do consider the heft, feel, and construction. Having more than one wooden spoon break I now look for a ‘reliable’ one – in my case with a hefty shaft and tight grain running along (not across) the shaft.
Most kitchen appliances do not lead with their reliability characteristics. If you’d ask for the MTBF of a wooden spoon, you most likely would get a very puzzled look and response.
The same for a car. The last time I bought a car I wanted one that was versatile, stylish, a hybrid, and reliable. I meant reliable in the sense I could count on the car to start and provide safe transportation. (I really want availability and safety and comfort, I suppose).
So, I asked the sales representative for the reliability data on the model of interest. She said all their cars are very reliable and even showed me a fancy four-color brochure with that very statement, ‘Very Reliable.’
No data, no probability of surviving for 5 years, not even a hint of an MTBF.
Then she went into the length of the power train warranty and how I could purchase an extended warranty, too.
Rather than explain the difference between warranty coverage and reliability, I moved on to other aspects of the discussion.
In business to business commerce we often find discussions about reliability. Solar power systems have to be reliable enough to be ‘bankable’, factory equipment has to be reliable enough to minimize the cost of ownership, and many data-sheets include life or failure rate information.
Years ago at a trade-show which had a lot of new and innovative devices, I overheard a short conversation.
The person behind the booth just finished explaining the wonderful new features of this personal assistant type gadget, including battery life, networking capability, speed, and integration ability.
“So, how long will it last?”, the interested party asks. He’s interested in reliability, I think, as the device is expensive and if it will work long enough the cost/benefit may balance out in favor of a purchase.
“It has a 3 month warranty.”
Hum, not long enough… “How long should it continue to work? What is the design or expected useful operating lifetime of the device?”
[that seems like a pretty clear request for something like reliability]
The sales person doesn’t know how to answer this question, so says, “I don’t know, I suppose if it isn’t dropped and the software kept up to date, it will last a long time [smiling broadly].”
Would any of these statements helped answer the question:
- “Oh, the MTBF is 50,000 hours.”
- “The design life is 5 years.”
- “We’ve done extensive testing and haven’t had a single reliability failure.”
- “This device meets all the UL and CSA requirements.”
- “I have used one of these for 2 months now and it’s working fine.”
How about something like this, “We expect 98% of devices to survive 5 years working as your personal assistant gadget in your portable business and home environments.”
Back to the actual conversation, at this point the sales person did say something like a very clear reliability statement and the potential buyer, said,
“Great, I’ll take one. Just be sure it is one of the good ones, not one of those two percent that are expected to fail.”