One of the benefits of reliability engineering is that failure happens.

Everything made, manufactured, or assembled will fail at some point. It is our desire to have items last long enough that keep working for us. Since failures happen, our work includes dealing with failures.

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We use our biases every day to make choices.

We select the beige sweater because we have a color bias concerning our sweaters.

Many of our biases help us quickly make decisions. We rely on biases to move through the day. Many of our biases are under the surface, unconsciously guiding our daily decisions. Mostly, biases are good or at least inconsequential.

The problem is the bias that shields us from achieving our goals.  [Read more…]

If you sort your Amazon search on ‘reliability engineering’ by price: low to high, you may find some interesting titles available for free or maybe a few pennies. Not one to resist a chance to fill another bookcase, it’s been a bit of a spending spree.

One of the reasons I am interested in older titles is to determine why MTBF is so prevalent today. So far, still looking and learning along the way.

There are many great books in our field. Sure, some are older. Some are not at all useful or helpful.

This book review is the first in what may become a monthly addition to the NoMTBF blog.

Today’s review is on the book, An Elementary Guide to Reliability (3rd) Third Edition, by G. W. A. Dummer and R. C. Winton. [Read more…]

One technique to calculate a product’s MTBF is to count the number of failures and divide by the tally of operating time.

You already know, kind reader, that using MTBF has its own perils, yet it is done. We do not have to look very far to see someone estimating or calculating MTBF, as if it were a useful representation of reliability… alas, I digress.

Counting failures would appear to be an easy task. It apparently is not. [Read more…]

Sample Size and Duration and MTBF

If you have been a reliability engineer for a week or more, or worked with a reliability engineer for a day or more, someone has asked about testing planning. The conversation may have started with “How many samples and how long will the test take?”

You have heard the sample size question.

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Learn to Notice MTBF Every Day

Did you notice the speed limit signs in your neighborhood today?

If like me, you went about your commute or regular travels relatively blind. You watched for the neighbor’s dog that jumped into the road last week, yet didn’t register seeing the speed limit sign.

It’s a cognitive burden to notice the mundane or known. [Read more…]

This may seem an odd article for the NoMTBF site. Stay with me for a moment longer.

Over the years of speaking out on the perils of MTBF, there has been some pushback. A few defend using MTBF. Here are three of the most common (maybe not exactly the best, per se) reasons to use MTBF. [Read more…]

Nearly everyone I’ve ever met doesn’t want or like their toaster to fail.

It will, and that is a bummer, as the quick and easy way to warm up the morning toast will be thwarted.

Failures happen. As reliability engineers, we know that failures happen. Helping others to identify potential failures, to avoid failures or to minimize failures is what we do best.

It is our ability to teach others about reliability engineering that allows us to be successful. [Read more…]

Here is a Challenge: Life Data Analysis

Some years ago a few colleagues compared notes on results of a Weibull analysis. Interesting we all started with the same data and got different results.

After a recent article on the many ways to accomplish data analysis, Larry mentioned that all one needs is shipments and returns to perform field data analysis.

This got me thinking: What are our common methods and sets of results when we perform life data analysis? [Read more…]