Speaking Of Reliability: Friends Discussing Reliability Engineering Topics | Warranty | Plant Maintenance

Failure and Hazard Rate Abstract Chris and Fred discuss the similarities and differences between two terms that many people think mean the same thing. Key Points Join Chris and Fred as they discuss the idea that a failure rate and hazard rate are the same, or are they? Topics include: What is the ‘hazard rate’? The rate at which functional products, systems or items fail. Think of human beings. There aren’t many people who are 100 years or older. But even though there aren’t many of them, the chances of them dying in the ‘short term’ is very high. So the ‘hazard rate’ is analogous to the frequency of something failing if it is still working. What is the ‘failure rate’? Depends who you ask … because some will tell you that the failure rate is the rate at which products, systems or items fail (without the word ‘functional’). Let’s go back to human beings. The frequency of people who are 100 years or older dying on any given day is relatively low, at least compared to the rest of us who are dying. And the reason for this is that even though really old people are more likely to die, there are fewer of them around. So the ‘failure rate’ can be seen as the height of the Probability Density Curve. Like the height of the bell curve. … and the ‘hazard rate’ can be seen as the height of the Probability Density Curve divided by reliability. To take into consideration that it only applies to functional products, systems or items fail. But … there are ‘repairable’ systems. If you replace or repair products, systems or items that ail, then there will always be replenishment. Meaning every system is always functional, so the hazard rate and failure rate become the same. And some people just think the failure rate is exactly the same as the hazard rate. … so use the definitions that best works for you, your organization, and limits confusion! Enjoy an episode of Speaking of Reliability. Where you can join friends as they discuss reliability topics. Join us as we discuss topics ranging from design for reliability techniques to field data analysis approaches. Download Audio RSS Show Notes The post SOR 943 Failure and Hazard Rate appeared first on Accendo Reliability.

Field and Operational Time Abstract Chris and Fred discuss a listener’s question about dealing with different ‘duration’ metrics for their field data … so how do we find things like ‘operating time’ and other age-related metrics that aren’t calendar time that simply aren’t there? Key Points Join Chris and Fred as they discuss how to work with a product’s whose age and usage are only available in terms of calendar time, but we are interested in things like ‘operational’ or ‘running’ time instead. Help! Topics include: Before you launch into analysis … what decision are we trying to inform? Focus on what you’re trying to achieve or inform. What decision is this for? Working out this decision lets you know how accurate the outcomes of your analysis are. If you only need an answer that is a ‘rough order of magnitude’ … then maybe you don’t need to waste too much time on this problem. What does this mean? Here’s an example. An engineer tested three DC converters from three different suppliers for three times the anticipated service life in terms of ‘running time’ for their complicated machine. Two of them didn’t fail at all. One failed, but right at the end of the test. Long story short … none of these three DC converters would cause the machine to fail if they were selected. So which one is the right one? The cheapest/sexiest/thinnest/lightest/one with the lowest supply chain risk. They are all ‘reliable enough’ for the machine … so there is no need to even use reliability to differentiate between each. But if we need a more accurate number? Then you need to do some digging. And depending on how deep you want to go … some more complex data analysis. If you have access to data like shelf life before sale, observed usage (odometer) readings from products being used and so on, you can come up with a distribution that describes the likely values for operational time based on calendar time. So if something fails after 300 days, you might be able to create something like a ‘bell curve’ that tells you the best guess at running time is 195 hours, with us being 90 % certain it is between 175 and 215 hours. Or … you might need the marketing team to launch some surveys and do some research. And if you know what the decision you are making is, you can work out how much money could be made or saved by making the right decision. And that might help the justification for things like surveys. Still not happy with this? What happens if you make the worst ‘assumptions’ regarding your analysis, so the analysis gives you ‘worst case’ and ‘best case’ numbers. If either of these numbers give you enough information to make a decision … then you are still good to go! Just focus on the decision … Enjoy an episode of Speaking of Reliability. Where you can join friends as they discuss reliability topics. Join us as we discuss topics ranging from design for reliability techniques to field data analysis approaches. Download Audio RSS Show Notes The post SOR 942 Field and Operational Time appeared first on Accendo Reliability.

Risk vs Reliability Abstract Carl and Fred discuss whether the reliability community should focus on the body of knowledge associated with risk or reliability. Key Points Join Carl and Fred as they discuss risk versus reliability, and how they interact in bringing about safe and economical products. Topics include: Risk as uncertainty Is everything focused on risk? Risk vs reliability = both Being able to characterize and understand risk is essential to making good decisions We live in a world of risk Reliability as performance, separate from reliability as safety Enterprise risk vs product or technical risk Our ability to fit reliability concerns into larger context of business concerns is important Reliability is a subset of enterprise risk Enterprise risk takes into account: economics, regulatory, geo-political, technical, and many other aspects Risk and innovation How to mitigate risk Scope of reliability Be aware of all forms of risk, influence what is within your scope Reliability works within transactional and design level Reliability is part of risk management process Enjoy an episode of Speaking of Reliability. Where you can join friends as they discuss reliability topics. Join us as we discuss topics ranging from design for reliability techniques to field data analysis approaches. Download Audio RSS Show Notes   The post SOR 941 Risk vs Reliability appeared first on Accendo Reliability.

When I Know it’s Not Right Abstract Carl and Fred discuss a question brought up at recent conference: what do you do when you are supposed to do something that you know is not the right thing to do? The context was reliability engineering and management. Key Points Join Carl and Fred as they discuss how to react when your customer or your management requires a certain method or approach that is not correct, and does not appear to be open to discussion. Topics include: Always maintain your integrity What to do when you are required to use MTBF, and there are better ways What to do when you are required to use MIL-STD-217, and there are better ways Reference final two chapters from our book “The Process of Reliability Engineering” Learn the soft skills: listening, formulating your ideas, communicating, presenting, summarizing, and others. Clearly communicate *why* there is a better way Consider doing it both ways: the right way and the mandated way: balancing budget Importance of influencing others Look at things from management’s point of view Be willing to move outside your comfort zone When to “lay your body on the track” Work on the source of the conflict “Checklist” mentality Style vs principle: Thomas Jefferson quote Learn to know the difference between style and principle; stand for principles Ask, what is the purpose? What are you trying to accomplish? Regulatory compliance: what if the regulation is not helpful? Enjoy an episode of Speaking of Reliability. Where you can join friends as they discuss reliability topics. Join us as we discuss topics ranging from design for reliability techniques to field data analysis approaches. Download Audio RSS Show Notes   The post SOR 940 When I Know it’s Not Right appeared first on Accendo Reliability.

When to Consider Reliability Abstract Kirk and Fred discuss at what point in the product development process should we consider applying reliability engineering to the concept and actual prototypes. Key Points Join Kirk and Fred as they discuss the reliability process and reliability tools and methods and when to apply them. Topics include: Reliability development of a new device or system should start with following good design rules, including design for reliability and design for manufacturing, as well as knowing the variations of the applications in the end-use environments. When we think of what type of electrical connectors to use out of the hundreds of types and manufacturers we should be able to estimate what the stresses that the systems will be subjected to during its life cycle. For instance If the use conditions result in high vibration or shock, then a locking connector should be used, versus one that relies on insertion friction. Design engineers many times have narrow view of the worst case user and cumulative fatigue damage by them. They may consider any use beyond the published use specifications is customer abuse, although most customers do not even know what the manufacturers specifications are. For instance, How many users do you think know what their smartphone specifications are? Product designers tend to design away from failure, but at the same time may assume that users will follow the use specifications, and also not consider the fatigue damage over time even if the use is within the maximum stress specifications. Enjoy an episode of Speaking of Reliability. Where you can join friends as they discuss reliability topics. Join us as we discuss topics ranging from design for reliability techniques to field data analysis approaches. Download Audio RSS Show Notes You can now purchase the most recent recording of Kirk Gray’s Hobbs Engineering 8 (two 4 hour sessions) hour Webinar “Rapid and Robust Reliability Development 2022 HALT & HASS Methodologies Online Seminar” from this link. Please click on this link to access a relatively new analysis of traditional reliability prediction methods article from the US ARMY and CALCE titled  “Reliability Prediction – Continued Reliance on a Misleading Approach” For more information on the newest discovery testing methodology here is a link to the book “Next Generation HALT and HASS: Robust design of Electronics and Systems” written by Kirk Gray and John Paschkewitz. The post SOR 939 When to Consider Reliability appeared first on Accendo Reliability.

Predicting the Unknowns Abstract Kirk and Fred discuss the world of reliability predictions and the issue of predictions when many, if not most of the causes of unreliability, are surprises. Key Points Join Kirk and Fred as they discuss use of good design rules and building in some margins of safety, but yet when the systems fail it’s usually a surprise. Topics include: It’s hard to know what safety factor, or strength margin, is really needed due to future variations in manufacturing and assembly. It is very difficult to know what the variations will be with only a hand-full of early prototypes as samples. There are many “design for” or what is known as DFx, , where the good design rules for environment, manufacturing and reliability, among other rules. These rules are necessary to make reliability designs. Boeing has had its share of many significant failures, as has happened in the Boeing  Max 8 MCAS, and the recent door plug failure on the MAX 9. Assembly or manufacturing errors may have been the cause of these failures. Do all you can during the design stage using CAD and multi-physics simulators to verify based on ideal components. Those software tools are getting much more capable. And then when you have actual physical hardware to test, use stress to find weaknesses that were not anticipated. Enjoy an episode of Speaking of Reliability. Where you can join friends as they discuss reliability topics. Join us as we discuss topics ranging from design for reliability techniques to field data analysis approaches. Download Audio RSS Show Notes You can now purchase the most recent recording of Kirk Gray’s Hobbs Engineering 8 (two 4 hour sessions) hour Webinar “Rapid and Robust Reliability Development 2022 HALT & HASS Methodologies Online Seminar” from this link. Please click on this link to access a relatively new analysis of traditional reliability prediction methods article from the US ARMY and CALCE titled  “Reliability Prediction – Continued Reliance on a Misleading Approach” For more information on the newest discovery testing methodology here is a link to the book “Next Generation HALT and HASS: Robust design of Electronics and Systems” written by Kirk Gray and John Paschkewitz. The post SOR 938 Predicting the Unknowns appeared first on Accendo Reliability.

Be Helpful Abstract Chris and Fred discuss the importance of being helpful when it comes to reliability engineering. After all, it is much easier to have people want to come to you as opposed to forcing them to do something they don’t want to. To be influential is to be helpful. Key Points Join Chris and Fred as they discuss how important it is to be helpful as a reliability engineer. Too many reliability engineers complain about not being heard or listened to. And it often starts with them not trying to be helpful. Topics include: Influence. Reliability engineers often complain about not being influential enough. That means people don’t listen to them. But the decision to listen or follow is an emotional one. And if reliability engineers aren’t there to help, then people decide to not seek them out. Which means you are not influential. You still need visionary leaders. And that is because to help employees, designers, managers, and manufacturers out, you often need to help them ‘look good’ in the eyes of their leaders. But if those leaders are so focused on slashing costs and schedule (which means there is a rush to build the ‘wrong thing fast’) then you are not going to be helpful when doing good reliability engineering. … so sometimes you need to ‘help’ leaders. This means finding ways to convince leaders to complete reliability and quality actions ‘today.’ And this means helping them see the connections. For example, let’s say a leader has historically been against focusing on quality and reliability. But we know that 25 % of their effort is focused on rectifying defects or problems during production. If there are 100 people in this organization, then simply halving the amount of ‘rectification effort’ effectively means that you now have 12.5 more full-time staff who can focus on other things. This might be all the help the leader needs to change direction. Enjoy an episode of Speaking of Reliability. Where you can join friends as they discuss reliability topics. Join us as we discuss topics ranging from design for reliability techniques to field data analysis approaches. Download Audio RSS Show Notes The post SOR 937 Be Helpful appeared first on Accendo Reliability.

Interpreting formulae and not just generating numbers … Abstract Chris and Fred discuss how formulae (or formulas!) can be very important … but it is way more important to understand what formulae represent, and how they work. Listen to this podcast if you want to learn more! Key Points Join Chris and Fred as they discuss how important it is to understand what formulae represent, including all those pesky parameters that are represented with Greek letters. Why is that? Topics include: What is the ‘mean’ or ‘average’ of something? Some of us might be able to quote a formula for the mean. But do you actually know what it is? Put simply … the mean is the ‘balance’ point of your data points if they sit on a pivoting plank. Think of the ‘balance point’ of the histogram of your data points. That’s it. What about the standard deviation? Well … once you get that histogram, find its moment of inertia (i.e. how hard it is to spin around) and then take its square root. Again … that’s it. But did you know that? OK … but why do I need to know how to interpret formulae? Take (for example) Weibull plotting. For those who don’t know what it is, it is just a special way of visualizing data that allows us to see failure characteristics if we know what to look for. If you know what the shape of these data points means, you can see where you need to service (i.e. when things start to wear out), or how many things are suffering from infant mortality. If you don’t know what equations mean, then all you can calculate are parameters, means, and other numbers that you won’t know how to help you make better decisions. Then there is error checking. If you know what your formulae and equations represent, then you can have a good guess at what the answer should be before you get the number. And this can help you make sure you didn’t make a simple error. If you are modeling the time to failure of something, and a computer tells you that the parameter ‘μ‘ of the normal distribution you use to model time to failure is negative, then you should immediately know you have a problem. Why? Because that parameter is the ‘mean’ or the balance point of data points that must be greater than zero. This approach has saved so many reliability engineers over the journey! Enjoy an episode of Speaking of Reliability. Where you can join friends as they discuss reliability topics. Join us as we discuss topics ranging from design for reliability techniques to field data analysis approaches. Download Audio RSS Show Notes The post SOR 936 Interpreting Formulae appeared first on Accendo Reliability.

Change Management Success Abstract Greg and Fred discuss organizational change management and behavior change.  Greg’s change management is sell the sizzle.  Fred’s is give them the steak.  Discover why? Key Points Join Greg and Fred as they share change management stories including tips and tools for success.   Topics include: What is change management? How can you induce change management and behavior change? What are leadership, management, and scientific methods for change management? Enjoy an episode of Speaking of Reliability. Where you can join friends as they discuss reliability topics. Join us as we discuss topics ranging from design for reliability techniques to field data analysis approaches. Download Audio RSS Show Notes   The post SOR 935 Change Management Success appeared first on Accendo Reliability.

Contingency and Risk Planning Abstract Greg and Fred discuss various situations where contingency and risk planning may be required. Key Points Join Greg and Fred as they discuss contingency and risk ‘what if’ planning.  Topics include: When should a contingency and risk plan be developed. How to develop a contingency plan. What are the critical elements of a plan. Enjoy an episode of Speaking of Reliability. Where you can join friends as they discuss reliability topics. Join us as we discuss topics ranging from design for reliability techniques to field data analysis approaches. Download Audio RSS Show Notes   The post SOR 934 Contingency and Risk Planning appeared first on Accendo Reliability.