In the article Calculating Network Reliability the lack of published analytical solution for dual-ring network reliability was highlighted. This article provides a neat solution and further challenges readers to offer their proof or prior publication reference. The solution and the author’s general proof will be presented at RAMS 2020.
I have worked in the field of reliability for a good many years. I have presented both beginner and advanced reliability engineering courses. I have even read several books. 🙂 But, across all this, component redundancy has never been explained beyond simple serial and parallel configurations.
So, it was a shock to my system to be presented with a scenario that couldn’t be solved using a simple parallel system.
My previous work had challenged me only as far as:
- Active parallel
- Stand-by parallel
- M-out-of-n parallel
- Keystone-component parallel
But now I was being challenged by a network that was none of these.
I was reading an article recently about Apple MacBook Pro keyboard issues, affecting the current generation of products, on which this article is being written. I also have an iPhone sitting next to me playing “music” whilst I wait for a call-center agent to reply on a travel issue. In both cases, I am dependent on their correct functioning. My past experience across many products is that my overall experience is also dependent on how product support is delivered in case of hardware failure.
Design and business choices strongly affect in-life support capability. They affect not only the basic ability to repair a product but also, through the cost and availability of spare parts, the economic policies for repair.
How do we influence and make these choices?
I joined the Reliability Belt training team in 2018 and have delivered 2 Reliability Green Belt and 1 Reliability Black Belt courses so far. This is article is a review of my experience and the feedback from the participants. Further information about the course is available on the Accendo website and on the Reliability Engineering Academy website.
This first article looks to the Reliability Green Belt. A future article will look at the Reliability Black Belt experience.
“Les, you were awesome. One of the characteristics I liked the most was your cadence of speech. The metered delivery of each word and concept was very effective for me and my style of learning. If the words and concepts get delivered too quickly, I don’t have enough time to connect with the concept, write down my notes, and still keep up with the next thing being said. I found your analogies and examples of real world applications to be very relevant and helpful. Overall, I feel I have received value well above my expectations for the course, and with your instruction I was able to hit the ground running on the first day I got back. Thanks for teaching the course, and I look forward to continuing my education with the Reliability Black Belt program.” — Chris, Reliability Engineer
Develop your skills – learn the tools and where to apply them
OK, let’s admit it. We don’t always make the best decisions. And of course, those around us don’t either. And yet, to deliver a product with all the best features to a customer or market, at a competitive price and in time to make the sale, and that also will have good reliability and long life, requires everyone to make the right decisions in a timely fashion all along the way. It doesn’t take many adverse decisions to introduce field issues, increase warranty claims and lessen product life.
Reliability management and engineering is all about using the best tools to guide our decision-making. Becoming a good reliability engineer, or decision-maker of any kind, is about learning those tools – including when and where to use them.
I have been working with clients recently who are keen users of FMEA. Getting engineers to contribute potential failures and their causes is not a problem with these clients, but ensuring that actions are correctly identified and followed up is not so easy. So, what goes wrong? What differentiates a good FMEA from a great FMEA? [Read more…]
Reliability engineering, analysis, management, testing… − Where do I get the skills and training to be really effective? University or College? In-house? Conferences? Webinars? Software or Equipment Suppliers? Journals? A colleague? − Do I need a Certification? − Do I need an integrated program, or only specific stand-alone techniques?
Everyone has to start somewhere. And if we are going to be smart about it, we should examine our needs and make a plan… [Read more…]
Plan Your Reliability Testing with Intent
I wonder how many product tests have been undertaken and nothing has been done with the results? Maybe development activities have moved on before any results are available? Maybe the test results didn’t provide the answers that were needed? Maybe the test wasn’t focused on the critical issues. In other words, cost, time and resources were wasted.
I will present a better way to ensure value is delivered and test results are acted upon. [Read more…]
We have “reliability” in our job title? Therefore, we must promote reliability across all our company products as our first priority?
If you believe that, then I believe you are a slave to reliability.
A project manager or design engineer comes to us and makes a proposal that would adversely impact product reliability. We’d reject it, yes?
Well, I believe, on both counts, we should first take a step back and review the alternatives. [Read more…]
Ensuring Reliability Data Analysis Leads to Positive Action
Convince, don’t confuse! Justify, don’t exaggerate!
Project managers want to deliver their product on time and on schedule. Design engineers want to believe that they have got it right. But your analysis, test results and field data suggest that there might be a problem. What do you do?
The key words here are “suggest” and “might be”. How should you present your evidence and analysis such that it doesn’t exaggerate with certainty, or confuse with statistics? How should you ensure that your conclusions lead to positive action? [Read more…]
We all probably know Fred’s fight against the use of “MTBF” as a default measure of reliability.
And I concur. “MTBF” offers the least insight to product reliability. It offers little to the user in terms of realizing the benefits of reliability.
However, we all would like to see products that deliver more appealing benefits; and reliability is a key factor. But reliability is only part of the equation.
Technical performance is important.
So is price. So is appearance. So is delivery. So is the customer: different customers may see the world differently. And so may your competitors.
So, we can’t all adopt the same measurement for reliability. [Read more…]