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

When to do Monte Carlo Simulation (… and what is it)? Abstract Chris and Fred discuss when you should do this thing called Monte Carlo simulation? … in fact … what is it? Key Points Join Chris and Fred as they discuss when and how Monte Carlo simulation can help you with reliability modeling and analysis. What is it anyway? Topics include: What is ‘Monte Carlo Simulation’? It is really simple. It essentially relies on a computer to randomly simulate things like how long it will take for a component to fail (once you have been able to model it with something like a Weibull distribution). If you have something like a switching system where a switch device will detect when a primary component fails, and then switches to a standby component, then Monte Carlo simulation can really help. The analytical approach means you need to come up with an equation that takes into consideration the reliability of the primary component, the reliability of the standby component before it is used, the reliability of the component of the standby component after it starts being used, and the reliability of the switch itself. All of which changes over time. Good luck with that! But Monte Carlo simulation can really help … especially if you make things even more complicated by trying to take into consideration repair. Where does the term ‘Monte Carlo’ come from? The Manhattan Project. Physicist Stanislaw Ulam wondered to himself how to work out the likelihood of being able to win the game of solitaire (based on a standard 52 deck of cards). Winning solitaire starts with being dealt a winning hand. Not all deals allow you to win solitaire. And there are 8.06 x 1067 different ways you can deal with a pack of cards. This is not possible to solve analytically. But Ulam realized that with emerging computing power, he could ask computers to randomly deal 52 cards and assess if the hand was winnable (or not). So computers could simulate (for example) 10 000 deals and find the fraction of winnable hands. This would be a good guess of the overall fraction of winnable hands. And if you wanted to improve the accuracy of this answer, you run more simulations. … and why was it called ‘Monte Carlo simulation?’ The Manhattan Project that this idea was so powerful, that it needed to be protected. So it needed a code name. So Ulam referred to it as ‘Monte Carlo’ simulation because his uncle enjoyed playing solitaire at the Monte Carlo Casino in Monaco. 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 923 When to do Monte Carlo appeared first on Accendo Reliability.

Many Ways to Estimate Reliability Abstract Chris and Fred discuss how we can go about estimating reliability … especially when you don’t have a lot of data, experience or other things that textbooks say you need to have to estimate reliability? Key Points Join Chris and Fred as they discuss how you go about estimating reliability, especially if your product or system is not mature or well-understood. How do you measure reliability early in the design process (for example)? Topics include: Start with the decision you are trying to inform. For example, if you are trying to work out which gasket or material is more reliable than another to inform your supplier choice, then you don’t need to have an incredibly accurate estimate. Are you instead trying to work out what specifications need to go into a document for a supplier’s component performance, then you simply might need a ‘best guess’ of all the other component reliabilities to get that right. And the less confidence you have in the ‘best guess,’ the more margin you might need in that specification. Is this going to be a problem? If not, then don’t bother doing more modeling or analysis. … so it is about the ‘confidence’ you need. Not every reliability measurement needs to be accurate to six significant figures. Focus on the decision first, and then actually talk about the confidence you need so that people don’t panic over getting a ‘perfect’ answer. Estimating reliability is primarily there to provide guidance. Too many organizations are all about having a number that can be put in a document, brochure or meeting minutes. Let’s say that we come up with a ‘best guess’ for a component at the start of the design process. As the design becomes more mature, do they still feel good about this number? If not … talk about it! Can this be accounted for in other components? Or will this break the bank? Just start thinking (and talking)! And don’t use parts count predictions … we have lots of webinars and podcasts on why not! 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 922 Many Ways to Estimate Reliability appeared first on Accendo Reliability.

Lifespan of an FMEA Abstract Carl and Fred discuss a reader question about what is called a “living FMEA.” Is this a good idea? How is it done? Key Points Join Carl and Fred as they discuss whether to update FMEAs with test and field information on an ongoing basis. Topics include: An updated FMEA needs to begin with a good quality FMEA, as baseline There is little value in updating a poor-quality FMEA Using FMEA to avoid repetition of problems You can update an FMEA from test and field failures FMEA needs to visually highlight the most critical problems Guidance: you don’t need to do FMEAs on everything Field lessons learned is important input to FMEAs, field problems can be potential failure modes FMEA is not the only tool; need to know when it is used and it’s limitations Generic FMEAs are used as input to new FMEAs, not copy-pasted Past FMEAs are used as input to new FMEA, helping to ensure past failures do not repeat Avoid a numbers game when assessing risk scales Consider use “living FMEA” or generic FMEA when dealing with variants of a design or 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 921 Lifespan of an FMEA appeared first on Accendo Reliability.

RCM and FMEAs Abstract Carl and Fred discuss a reader question on FMEAs that involve maintenance. Specifically, can a Design FMEA have causes that are maintenance related? Key Points Join Carl and Fred as they discuss Reliability Centered Maintenance, and the role that FMEA plays in doing RCM projects. Topics include: RCM includes an FMEA front end. What is the nature of the FMEA that supports RCM? How to narrow down the equipment that needs RCM What to do when items need to be replaced too often Types of FMEA, the same fundamentals apply Design FMEA can improve maintainability, start with Functions Causes in Supportability FMEAs should be taken to “maintenance actionable” level Causes in Design FMEAs should be taken to root cause and associated mechanism of failure RCM uses “Design Logic Diagram” as part of identifying risk Using RCM to develop maintenance tasks To get better involvement, focus on the most important issues 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 920 RCM and FMEAs appeared first on Accendo Reliability.

Details and Plans Abstract Greg and Fred discuss why and how the triple constraints of a project: schedule, cost, and scope variances result in risks that can result in project failure. Key Points Join Greg and Fred as they discuss schedule risk, cost risk, and scope risk.  Topics include: What are schedule, cost, and scope risks? How do you measure each? How can each contribute to project failure? How can you manage and mitigate these risks? 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 919 Details and Plans appeared first on Accendo Reliability.

Plug and Pray Abstract Greg and Fred discuss why engineers plug numbers into a formula not really knowing why or what they are doing.  At best, this is called ‘plug and play.’  At worst, this is called ‘plug and pray’ the formula works. Key Points Join Greg and Fred as they discuss the challenges of why professionals see a formula and pray it gives them the ‘right’ solution, but not really understanding the formula. Topics include: What is ‘plug and pray.’ Why do engineers and professionals do this? What are the risk consequences if the formula and problem solving approach is wrong. What can professionals do to prevent this risk. 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 918 Plug and Pray appeared first on Accendo Reliability.

Bad History Challenge Abstract Kirk and Fred discuss how to deal with those who have said that they tried using the HALT methodology with a past project but did not find any benefit from it. Key Points Join Kirk and Fred as they discuss the situation where a we are trying to introduce a new methodology for reliability and a key player on the team that we have to win over says they tried it and it didn’t work. Topics include: Almost any critical reliability development process, whether DFMEA, HALT, or modeling, can be poorly planned or executed, resulting in a bad outcome and leading to the dismissal of the new strategy before someone can try it at a new company. Companies with good field failure data and root cause analysis should be able to identify many of the causes of failure, such as loose screws or connectors causing failure, and how stress testing can stimulate detection in a HALT evaluation. HASS is an expensive process to use for the long term. HASS should be only initially during the early production stage for some products if they are made as robust as standard technology allows and the manufacturing processes are stable. Semantics can matter, and it could be a good idea to call a new method or process by a different name, even though it is fundamentally the same process, to overcome the resistance to change. 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 917 Bad History Challenge appeared first on Accendo Reliability.

Cycles or Time Abstract Kirk and Fred discuss whether we should use time or number of cycles or total time a product has been available for use. Key Points Join Kirk and Fred as they discuss a question from a listener on whether it’s better to use time or cycles as a reliability metric. Topics include: As with most of our discussions, the decision to use cycles or total time depends on the type of system you are measuring. In pumps, valves, and other mechanical systems, the time between use can significantly affect wear and fatigue damage as seals and bearings lubrication may evaporate or its viscosity changes with temperature. Using an electro-mechanical system continuously and not having many on-off cycles results in different mechanical wear effects versus using the system once daily.  Starting a warm car engine is much less stressful and damaging than starting an engine after it has cooled down. The same is valid with electronics assemblies, especially in power electronics. Many products can log the cycles and total power on time, which differentiates between cycling and frequency of processes or on-off cycles. 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 916 Cycles or Time appeared first on Accendo Reliability.

Creating Reliability Awareness Abstract Chris and Fred discuss how to help me, you and the people around us more aware of reliability (and reliability engineering)? Good question! Key Points Join Chris and Fred as they discuss how we go about creating reliability awareness in an organization. The answer isn’t always a webinar. And the answer has to include management and decision-makers and make it stick! Topics include: The issue is motivation (not awareness). Should you need to be aware of what the issues are, what options are available to address them, and so on? None of this works if people aren’t motivated. So you need to start by explaining how reliability engineering solves problems (not just product failures). Which has the cool benefit of reducing time to market, money spent on crises during production, and so on. It starts with leaders. They need to be the people who are the most motivated (and aware) of what reliability engineering can do. If they aren’t interested in turning up … you are wasting your time. Don’t blame suppliers. Everything starts with you. If all you want to talk about to your suppliers is budget, schedules, milestones, payment deadlines, qualification tests, and the rest, then you are practically forcing them to only be aware of these things. If you show that you aren’t aware of reliability as a customer, it will invariably be because you focused on everything else that is in the contract that you prefer to talk about. And on it goes. 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 915 Creating Reliability Awareness appeared first on Accendo Reliability.

Required to Use MIL-HDBK 217? Abstract Chris and Fred discuss Military Handbook 217 Version F for the ‘Reliability Prediction of Electronic Equipment’ or MIL-HDBK 217F … and why being forced to use it is borderline evil. Key Points Join Chris and Fred as they discuss MIL-HDBK 217F contains lots of estimates of failure rates of different types of electronic components (tantalum capacitors, surface-mounted resistors and so on). Which was released in 1991 (i.e. … a long time ago) and is nothing but best guesses by faceless people. So what happens when customers demand you use it? Bad stuff. Topics include: It makes your system less reliable. True story. If a customer demands you use MIL-HDBK 217F, then you are essentially forced to use the types of components in those handbooks that have the best failure rate. But the pecking order for today’s electronic components has changed remarkably (remember that MIL-HDBK 217F came out in 1991). So there are lots of manufacturers who knowingly take out more reliable components and replace them with components that have a better failure rate in MIL-HDBK 217F. Madness. It makes you stop thinking about reliability. Looking at you defense and governmental customers. Instead of you actually learning about what you need to look for in the products your suppliers give you, you just want a number that you can put in a report. So you essentially tell your suppliers that no matter how hard you work on the quality and reliability of your components, they will always be assigned the same arbitrary, outdated number. Lots of madness. Where did the numbers found in MIL-HDBK 217F come from? There is no formal answer to this question. But industry insiders know that it is based on the precious few companies (perhaps as low as five) who were willing to share their reliability data (without knowing how robust these numbers were). All the gaps were filled in by historical military data dating back decades (to the 1960s). So do you want to use MIL-HDBK 217F to estimate smartphone or desktop computer reliability based on an ad hoc smattering of data that was put together before anyone knew these products were even feasible? Incredible amount of madness. 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 914 Required to Use MIL-HDBK 217? appeared first on Accendo Reliability.