Get Your MTBF Estimation Here
MTBF is a magic method for predicting time to failure for your new design. On this page we present to you the fastest way to achieving MTBF.
Maybe The Best Function ever! [Read more…]
The MTBF Estimation Wizard
Why Do a Parts Count Prediction?
Why Would You Do a Parts Count Prediction?
Is there any useful result from a parts count prediction?
In most cases that I’ve seen parts count predictions used they are absolutely worthless. Worse, is the folks receiving the results believe they are accurate estimates of reliability performance (or at least use the results as such).
In my opinion, the range of parts count prediction methods and databases harm the field of reliability engineering.
We need to call out the poor results, promote better practices, and stop the vapid use of such a poorly understood tool. [Read more…]
MTBF and Mean of Wearout Data
MTBF is Just the Mean, Right?
A conversation the other day involved how or why someone would use the mean of a set of data described by a Weibull distribution.
The Weibull distribution is great at describing a dataset that has a decreasing or increasing hazard rate over time. Using the distribution we also do not need to determine the MTBF (which is not all that useful, of course).
Walking up the stairs today, I wondered if the arithmetic mean of the time to failure data, commonly used to estimate MTBF, is the same as the mean of the Weibull distribution. Doesn’t everyone think about such things?
Doesn’t everyone think about such things? So, I thought, I’d check. Set up some data with an increasing failure rate, and calculate the arithmetic mean and the Weibull distribution mean. [Read more…]
Is Using MTBF Habit Forming?
With Enough Reinforcement, MTBF Use Becomes a Habit
A habit you should examine and stop.
At first, I wondered if MTBF use was addictive, yet I thought that comparison would belittle the very serious issues of those with addictive behaviors. Using MTBF does not generally cause a person harm, while poor decision based on it might harm the organization.
I find those that regularly employ MTBF do so without thinking about it too much. If someone mentions reliability, they think MTBF. Automatically.
Habits help us reduce cognitive load and make our life simpler. For example, do you need to focus on how to put on your shoes every morning? I’m personally happy my habit skills allow me to remember how to drive safely without the intense focus required the first time I got behind the wheel.
Let’s examine how to tell if someone has the Habit of MTBF use and what you can do about it. [Read more…]
Fundamentals of Environmental Testing
Fundamentals of Environmental Testing
podcast episode with speaker Fred Schenkelberg
One of the elements of reliability concerns where and how the product will be used. This includes understanding the environmental stresses (such as wind, insects, and temperature) as well as the product’s handling, usage frequency, throughput, and other relevant factors.
In some cases, we need to evaluate our product’s ability to survive the expected environmental stresses. Conducted well, this testing will provide vital information to the design team about the product’s capabilities. It also may reveal design weaknesses.
Let’s explore when and how to identify which types of environmental testing should be done. The intent is to conduct specific environmental tests that will provide value to the organization and its customers. Doing any environmental test just because we can is not a valid reason to do so.
Learn Reliability, Not Just MTBF
MTBF is a Starting Point, Only
MTBF is not meant to be used for anything other than teaching someone new to reliability how the various functions and tasks work.
Using MTBF in the real world is an oversimplification to the point of being less then useful. Possibly even harmful.
You see MTBF is books, articles, and papers, often with the caveat of the assumption to simplify the math to illustrate the process or concept. Hence, does not apply for actual use. [Read more…]
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? [Read more…]
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. [Read more…]
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. [Read more…]
Fundamentals of Success Testing
Fundamentals of Success Testing
podcast episode with speaker Fred Schenkelberg
Product life testing is expensive. Thus, many seek ways to minimize the cost. Two common methods is to use the fewest samples that may lead to a meaningful result, and using acceleration methods to shorten test times. Designing a test based on the pass/fail (binomial distribution) approach provides a path to using very few samples, providing a clear pass/fail result, and is relatively risky.
Let’s examine the success testing approach, the assumptions, benefits and faults. Plus, what other options you may have available to get the information concerning expected product/component life. Knowing the details of success testing enables you to use it when it’s appropriate and when to avoid its use.
5 Ways Your Reliability Metrics are 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. [Read more…]
RM 172: From Chaos to Control: Steering ERP Projects Back on Track with Chintan Sutaria
From Chaos to Control: Steering ERP Projects Back on Track with Chintan Sutaria
Today we’re diving into a topic that keeps many executives awake at night—ERP implementations. More specifically, why so many of them fail and, perhaps more importantly, how to fix them midstream before they derail your operations.
Joining me today is someone who knows this space inside and out—Chintan Sutaria. Chintan grew up working in an EMS business from a young age, gaining firsthand experience in the unique challenges of our industry. His career path took him into the world of business process consulting at some of the largest Big 5 firms, and he has since worked with numerous EMS companies on a wide range of projects.
Many of you may recognize Chintan as the founder and former CEO of CalcuQuote, a well-known supply chain management software solution for the EMS industry. Recently, he founded, OpenJar, a consultancy dedicated to helping electronics manufacturers navigate complex business challenges—including ERP implementations.
We’ll discuss his new company as well as his recent blog post, “Why Your ERP Implementation Failed (and How to Fix It Midstream)”, explore common pitfalls, and uncover strategies to steer your ERP project back on course.
Chintan’s Company
OpenJar
https://openjartech.com
The Variety of Statistical Tools
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.
[Read more…]The Rule of 3 Significant Digits
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. [Read more…]
A Couple of Questions for You Concerning MTBF
Do make compromises around gathering and analyzing data since you only need to report MTBF?
Do you use MTBF (exponential distribution) based test planning when you know the product has a non-constant hazard rate?
These questions came up this week via email looking for advice when directed to ignore the actual situation and just do what the customer wants.
I’m traveling this week, rather jet-lagged today, so going to keep this one short.
How would you answer these questions? What advice would you give someone using exponential based reporting, test planning, or data analysis approaches knowing the customer expects that process yet the data and your experience suggest you should use another method (Weibull or MCF, for example)?
Please add you comments below and let’s prepare a list of what one should say or use to respond to such actions.
