Reliability is about making the right decision, each time.
A common role during a first assignment as a reliability engineering is to answer a question or accomplish a task. It may help someone to make reliability decisions.
We may be asked, as I was, how long will this new product function during use? The director of engineering wanted to know if the new design was reliable enough to meet the customer’s requirements concerning reliability. He didn’t ask it that way, yet he did have a question that needed answering.
Sometimes we run a batch of tests, conduct failure analysis on field returns, or compare the durability to two vendor subsystems. In each case, there is a question to be answered.
A decision to be made by someone else. Continue reading Enabling Great Reliability Decisions
Field Failure: A Quality or Reliability Problem
When my car fails to start, as a customer I only know that my car didn’t start.
When my phone fails to turn on, or the dishwasher leaks, or the printer jams, I only know I’ve experienced an unwanted outcome.
I really do not care, at the moment, why the coffee maker is not producing my morning cup of coffee. My first thought is ‘now where do I find a cup of coffee?’ As a reliability engineer I’m naturally curious about what caused the failure and can I fix it immediately to get the morning cup brewing.
My thinking does not classify the failure or the source of the failure as a quality or reliability problem. Then why is it that some organizations split reported field failures thus? Continue reading Field Failure: A Quality or Reliability Problem
How Does One Change an Industry
Jobs at Apple has done it. You can, too.
Change an industry. The advent of iTunes and iPods forever changed how the world buys and listens to music.
While Jobs had the resources of Apple to help make the change happen. It still started as an idea (may or may not have been Jobs’ idea, I don’t know). It grew and created enough momentum to effect a change across an entire industry.
Change is hard.
If you have tried to help your team move in a new direction or consider the reliability risks present in the current design, then you know change is difficult to make happen. You most likely have been successful a few times, and not a few also. I know I’ve crashed into the rocky spit more often than I can count. Continue reading How Does One Change an Industry
Reliability is Not Metrics, It’s Decision Making
MTBF, KPIs, yield, return rate, warranty… bah!
We may use one or more of these when establishing product reliability goals. When tracking performance. When making decisions.
Goals, objectives, specifications, and requirements, are stand-ins for the customer’s experience with the product.
We’re not trying to reduce warranty expenses or shouldn’t be solely focused on just that measure. We need to focus on making decisions that allow our product deliver the expected reliability performance to the customer. Continue reading Reliability is Not Metrics, It’s Decision Making
5 Ways Your Reliability Metrics and Fooling You
We measure results. We measure profit, shipments, and reliability.
The measures or metrics help us determine if we’re meeting out goals if something bad or good is happening, if we need to alter our course.
We rely on metrics to guide our business decisions.
Sometimes, our metrics obscure, confuse or distort the very signals we’re trying to comprehend.
Here are five metric based mistakes I’ve seen in various organizations. Being aware of the limitations or faults with these examples may help you improve the metrics you use on a day to day basis. I don’t always have a better option for your particular situation, yet using a metric that helps you make poor decisions, generally isn’t acceptable.
If you know of a better way to employ similar measures, please add your thoughts to the comments section below. Continue reading 5 Ways Your Reliability Metrics and Fooling You
The Variety of Statistical Tools to Support Your Decision Making
My wife and I moved to a new home last year. We have yet to organize our tools.
The bedroom and kitchen are now organized. We, for the most part, can find the sweater or pan that we’re seeking.
No so for our tools in the shop. We have an assortment of hand tools for painting, home maintenance, yard work, and woodworking. In our previous home, we had the tools on pegboards, on shelves, in cabinets. We could find the right tool for the job at hand quickly. We’ve avoided the tool aisle at the hardware store recently, as we were sure we had the tool we need in the jumbled mess in our garage already. Still haven’t found it, though.
Have you noticed the number of statistical tools available? It’s like visiting a well-stocked tool store. There are basic tools like trend charting and advanced tools like proportional hazard models. Let’s explore the available tools a little so you can quickly find the right tool for the question or problem you are facing today. Continue reading The Variety of Statistical Tools
Two people have shaped how I guess an answer.
Their comments and guidance have tailored how to form a quick estimate, my ability to articulate a hunch and the effectiveness of those guesses.
You probably guess or make a rough estimate regularly. How good is your gut feel? Do you keep track and score yourself?
Making an estimate should be second nature for you. It’s not something to do in public, too often. The practice can aid you in numerous ways. Continue reading The Rule of 3 Significant Digits
Teaching Reliability is Part of Your Role
Nearly everyone I’ve ever met doesn’t 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 out ability to teach others about reliability engineering that allows us to be successful. Continue reading Teaching Reliability is Part of Your Role
Math, Statistics, and Engineering
In college, Mechanics was a required class from the civil engineering department. This included differential equation.
Luckily for me, I also enjoyed a required course called analytical mechanics for my physics degree. This included using Lagrange and Hamiltonian equations to derived a wide range of formulas to solve mechanisms problems.
In the civil engineering course, the professor did the derivation as the course lectures, then expected us to use the right formula to solve a problem. He even gave us a ‘cheat sheet’ with an assortment of derived equations. We just had to identify which equation to use for a particular problem and ‘plug-and-chug’ or just work out the math. It was boring. Continue reading Math, Statistics, and Engineering
The Dirge of the MTBF Bias
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. Continue reading The Dirge of the MTBF Bias
Book Review: An Elementary Guide to Reliability
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 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. Continue reading Book Review: An Elementary Guide to Reliability
When Do Failures Count?
One technique to calculate a product’s MTBF is to count the number of failures and divide into 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 was a useful representation of reliability… alas, I digress.
Counting failures would appear to be an easy task. It apparently is not. Continue reading When Do Failures Count?
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 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.
Continue reading Sample Size and Duration and MTBF
Learn to Notice MTBF Everyday
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. Continue reading Learn to Notice MTBF Everyday
The 3 Best Reasons to Use MTBF
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 push back. A few defend using MTBF. Here are three of the most common (maybe not exactly the best, per se) reasons to use MTBF. Continue reading The 3 Best Reasons to Use MTBF