Your Reliability Engineering Professional Development Site
All articles listed in reverse chronological order.
Becoming an ASQ CRE is one milestone in your career. It involved gathering experience and studying the broad reliability engineering body of knowledge.
It also involved an ongoing application of what you know and learn. I’ve found being a reliability engineer involves learning about materials, designs, systems, people, and tools & techniques. Mastery takes time and a good library. [Read more…]
Ideally, in every design of every component, the stress–strength relationship looks like this figure. The stress is well below the strength.
This implies there is very little chance of failure due to the element being overstressed.
Also, ideally, we fully characterize all stresses and all strengths for each element of a product. This is generally difficult to accomplish and it is rarely done to that extent.
Every once in a while I see a comment that by following the HALT methodology you will “over design” a product.
Many question at what point or operational limit do you quit increasing the stress-strength margins. Those who hold this view of HALT do not understand the essence of what was Gregg Hobbs’ principles and paradigm shift. [Read more…]
Take Action Today to Improve How Your Organization Talks About ReliabilityYou know the perils of MTBF use. The widespread misunderstanding and mis-use. You know about how MTBF treats your data poorly.
You also know everyone around you uses MTBF. Your industry uses MTBF. And, now one likes change, least of all about metrics concerning reliability.
As I said to a friend this morning, “The madness has to stop.”
And, you feel that say way. So, what are you going to do about it? Here are five things you can do today.
Encourage five of your colleagues to check out and subscribe to this site, www.nomtbf.com.
Ask a vendor how they determined the MTBF value they are presenting on the data sheet? What evidence supports that claim and what assumptions are included (often unstated)?
The next time you hear someone mention MTBF, ask them what do they mean? And, than ask what percentage of items should survive a year? If they are not consistent — you found a learning opportunity.
Write a blog post for the www.nomtbf.com site. What have you done to encourage better understanding of reliability concepts in your world? Share you hints, tips, stories, and advice here.
Pick one for today and do as many as you can. What would you add to this list? What kind responses are you receiving when you speak out about the perils of MTBF.
Keep up the effort. Together we are making progress. Thanks for the support.
Embarking on a product development project contains many aspirations, including that the product should work as expected.
The device functions and does so over time. Enough time for the customer to deem the device reliable.
That is one way to approach setting a reliability goal for a project. Estimate what will delight the customer. Set a target for how long without failure your new design function.
The goal provides a focus for the team. [Read more…]
Reliability or life testing involves estimating the expected durability over time of an item.
This may be an entire system, a product, or an individual component. We may also focus on an element of a component, such has a material property.
At the end of the testing, we want to say something meaningful about the expected performance over time. [Read more…]
Many years ago people would complain about “cheap Japanese” products, but today few people would associate Japanese brands with poor quality.
The turn-around is widely attributed to Deming, and Taguchi, and Juran, and other evangelists who taught not only the tools and processes but also the long-term benefits that can be realized when a company adopts good practices and a culture of quality.
Today I hear people complaining about poor quality in Chinese-made parts and products, and there have been several widely-publicized incidents (see Aston-Martin and counterfeit parts).
Many customers have decided to move their production and seek part suppliers in other locations, including “re-shoring” to North America, in part because they’ve concluded that any cost savings due to cheaper labor are outweighed by the costs of poor quality.
It’s hard to say whether this will have a negative impact on the worldwide consumer perception of Chinese brands such as Lenovo, Haier, and others.
How to Translate Customer Expectations About ReliabilityAs a customer when I purchase a new car, a toaster, or a pump for my production line, I expect it to work. To Just Work. As a reliability professional, I also have the language to specify what I mean by, ‘just work’.
Customers that are not reliability engineers do not accurately specify what they mean by ‘it should just work’. So, we have to do a little extra to help translate that they want into specifications that we (manufacturer of the item) can create and deliver. [Read more…]
A common question concerns the warranty period.
How long should we, the manufacture guarantee that our product will work as expected? Do we include limitations or not? How do we decide? [Read more…]
Highly Accelerated Life Testing (HALT) is a technique to expose weaknesses or faults with a product.
HALT uses individual or combined stresses in a step stress approach to quickly apply sufficient stress to reveal defects.
HALT is not a specific chamber or fixed set of test conditions. It is an exploratory process to reveal weaknesses in a design.
The product development process naturally includes a check step, to determine if the expected functions of the product work as expected.
Some teams then add a measured amount of stress (temperature, vibration, dust, load, etc.) to the product to explore functionality at elevated stress levels. [Read more…]
I endured a difficult conversation with a project manager yesterday. The meeting agenda included an initial discussion about the product development reliability plan. She agreed that we needed to identify risks and provide feedback to the team concerning product reliability. [Read more…]
Here’s a short list of terms related to warranty management. Often is the words we use that matter and understanding the language of warranties is one step in mastering warranty management.
A promise made to the buyer of an item that the manufacturer (seller) will repair or replace the item if necessary within a specific time period. [Read more…]
A recent LinkedIn discussion addressed the question of the best strategy for dealing with poor supplier performance.
A lot of the respondents seemed to advocate a punitive approach, either threatening the loss of future business if performance doesn’t improve, or combing through the terms & conditions of the contract for enforcement language.
I’ve always thought that there’s a lot of similarity between managing suppliers and managing subordinates, and I wonder if some of these same people threaten their teams with punitive actions when individual performance doesn’t meet expectations. [Read more…]
MTBFMean time between failure or mean time before failure is very common. The common definition describes MTBF as a reliability measure that is calculated by tallying operating hours and dividing by the number of failures. Intuitively this is the average time until a failure occurs. Mathematically it is the inverse of the failure rate. Generally used for repairable systems. [Read more…]
In short, you probably do, better reliability performance the better the brand image.
When I’m making a purchase I prefer to buy items that I either have personal experience work well over time (reliable) or have many comments and reviews noting the durability.
As a reliability engineer, I am often asked what kind of car I drive (a Toyota Highlander, if must know). Reliability does matter -not only to me- it matters for many making a buying decision.
When a product’s actual reliability performance exceeds the customers expected reliability performance, the customer may consider the product reliable. This experience builds and when supported by other experiences from the same brand, increases brand equity. High brand equity permits a price premium, increased brand loyalty, and increased positive word of mouth support. [Read more…]