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

Reliability Assumptions Abstract Carl and Fred discussing the broad subject of assumptions, and how they impact reliability analysis and applications. When are assumptions good and when are they questionable? Key Points Join Carl and Fred as they discuss how to evaluate the efficacy of assumptions that are used in reliability programs or analyses. Topics include: What assumptions should we be wary of? How do we know if assumptions are valid or not? What are some of the common assumptions that can derail a reliability program or give wrong information? What assumptions tend to work in which circumstances? The first step (and it is not always easy), is being aware when assumptions are being made. Assumptions are often being made glibly or haphazardly. Too often, assumptions are not examined or even known. Consider the circumstances that affect when an assumption is OK or not OK. Beware of “blanket” assumptions. What evidence do you have? Challenge your assumptions, and those of others. Ask “why.” Document the assumptions that go into an FMEA or a reliability analysis. When is Exponential Distribution valid or not? What about different environments, does that change the assumptions? Assumptions related to failure mechanisms. 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 Related Topics SOR 547 When and Why Around Assumptions(Opens podcast in a new browser tab)   The post SOR 834 Reliability Assumptions appeared first on Accendo Reliability.

FMEA Occurrence Question Abstract Carl and Fred discussing a question received by an Inside FMEA reader on the subject of FMEA occurrence rating. Key Points Join Carl and Fred as they discuss assessing the occurrence rating in an FMEA, and the various applications and methodologies. Topics include: Why is occurrence part of FMEA? The efficacy of using FMEA occurrence rating to estimate reliability. Objectives of different types of FMEAs. Why occurrence is associated with the *cause* of failure mode. Method for assessing occurrence rating involves at least three inputs: field data for similar products (if available), prevention controls for the cause of failure, and degree of change from previous design. The purpose of occurrence rating in a Design FMEA or Process FMEA is not to estimate reliability. It is to help prioritize risk. Beware of occurrence rating that are all the same value. The assumptions going into an FMEA are important. Scale level of 1 – 5 versus 1 to 10. Are occurrence rankings subjective or objective? Keep in mind the purpose of FMEA and use occurrence to further that purpose. 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 Related Topics Understanding FMEA Occurrence Risk – Part 1(Opens article in a new browser tab)   The post SOR 833 FMEA Occurrence Question appeared first on Accendo Reliability.

What is Your Approach Abstract Chris and Fred discuss your approach for estimating the reliability of a new product, with new technology, manufactured in a new facility? … wow! Key Points Join Chris and Fred as they discuss how you can go about understanding the reliability performance of something brand new. Where do you start? Topics include: What will keep you up at night? You can’t analyze or test to exhaustion … even if you have a pretty good idea of how your product works. So you need to use ‘critical thinking’ to prioritize a list of likely weak points. These are the things that are going to drive reliability. There will be many hundreds (or thousands) of other, less important ways your product can fail. For those, you can use ‘best guesses,’ ‘expert judgment,’ estimates from literature, or other less robust information sources. But those VITAL FEW weak points need to be understood and analyzed further. So where do we start? (1) Prioritize risks. This starts with the VITAL FEW ways your product will fail but then moves on to the consequences of failure. Are some failures a bigger deal than others? … hint – yes. You need to come up with your own analysis activities and your own tests … not a list of tasks a standard says you need to do. (2) Decisions. What decision are you trying to inform? Are you trying to estimate (2-year) warranty reliability? This could change everything when it comes to you trying to understand the reliability of your product. But not only is the decision important, knowing when the decision needs to be made is just as important. If the decision needs to be made two weeks from now before you move into production, then you can’t undertake a 6-month academic study. (3) What needs improvement. This can come from an understanding of a previous model, or a Failure Modes and Effects Analysis (FMEA), or any other source of information that sheds light on your product. But a reliability estimate is just that … an estimate. Knowing what will fail if there is a slight change in how you think customers will use your product (or any other slight change in operating conditions or assumptions) is vital … and something you probably need to address. … don’t let a good opportunity for change slip away. Corporate knowledge is wonderful. Experience is great. But the best time to set the tone for a relationship is at the start. So if you are going to be using a new facility, or new team to make something, emphasize things like Statistical Process Control (SPC) or Process Capability Analysis (PCA) or transparency in relationships or anything else you think will help guarantee success moving forward. It is much easier to do this at the start as opposed to 2 years later, when change is often resisted as a critique of ‘poor performance.’ 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 Related Topic SOR 655 Hints to Have a Proactive Reliability Program(Opens podcast in a new browser tab)   The post SOR 832 What is Your Approach appeared first on Accendo Reliability.

Setting up an ORT Abstract Chris and Fred discuss what it means to establish an Ongoing Reliability Test (ORT) … or is it an accelerated test? … or the MTTF? Key Points Join Chris and Fred as they discuss a question that was asked by one of our listeners … can I complete an Ongoing Reliability Test (ORT) by accelerating life (with an Arhenius model) by increasing the temperature, or testing to failure to find the MTTF? Well … we don’t know? Topics include: What is being asked? It is not uncommon for us to sometimes get confused about what sort of test we are doing. This often comes from not understanding the decision we are trying to inform. Because accelerating stresses creates an Accelerated Life Test (ALT) where we essentially make our product wear out faster by stressing it more … and the MTTF is simply trying to measure one of the many ways of characterizing a ‘typical’ time to failure. Why do we need ORT anyway? Technically … we should be able to characterize reliability during production. So why do we need ORT? Usually to understand how a changing product is influencing reliability. Is a seal swelling? Is operating temperature higher than anticipated? You need to have a good understanding of the likely or dominant failure mechanism. What are you trying to do? What is your purpose? Without knowing this … we can’t help our listener! But there is a lesson here for you. Before you do anything, work out what you are trying to do. Link it to a decision. What information does that decision need? GO from there. … and a note on ALT. Don’t assume stuff. Don’t assume acceleration is caused by temperature (you can easily confirm this). Don’t assume an activation energy (you are wrong … and it is easy to find the right one).  Don’t start with not understanding likely or dominant failure mechanisms (it’s like going on an adventure without an idea of where you are trying to go). 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 Related Topic Introduction to Ongoing Reliability Testing(Opens article in a new browser tab)   The post SOR 831 Setting up an ORT appeared first on Accendo Reliability.

Dealing With Product Characteristics Abstract Dianna and Fred discussing engineering projects and dealing with product characteristics and requirements. Key Points Join Dianna and Fred as they discuss a listener’s question about dealing with product characteristics. Topics include: How Reliability Engineers can help with requirements by asking questions and giving feedback. Ways to evaluate requirements. Plastic pigments, phoneless phones, game consoles that warm fried chicken, sneakers that order pizza 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 Dianna and Fred talk about a listener’s question about working with product requirements. Reliability Engineers can help by giving feedback on requirements, so the team is clearer about them. Some questions to ask: Which requirements are important? Not all requirements are as essential as others. Which requirements are not well understood? This could indicate a risk to the project or product. What problem are we trying to solve? Ultimately, we’re creating something to be used by someone. Can we detect it: measure or otherwise verify? Ways to evaluate requirements: Ask the team: Get an informal prioritization of the important requirements. Requirements Matrix: compare them to identify competing or repeating requirements. Urgent/Important Matrix: from the user’s perspective when using the product. Critical path of a project: Identify risks of the project because of the unknowns in the requirements. FMEA: Done early and often to prioritize failures and safety. Requirements can evolve as we learn more about the product through its development. Trade-offs are probably going to be needed, which is going to lead to changes. Related Topic SOR 742 Reliability and Quality(Opens podcast in a new browser tab)   The post SOR 830 Dealing With Product Characteristics appeared first on Accendo Reliability.

New Ways to Break Things Abstract Dianna and Fred discussing new innovations from a reliability point-of-view: how is this new stuff going to break? What are going to be the new ways to break things? Key Points Join Dianna and Fred as they discuss up-and-coming, new technologies and what that means for the reliability profession. Topics include: Has the pace of innovation exceeded our interest? Where has our sense of wonder gone? Reliability Engineering is an important part of innovation. fusion reaction, printing, rockets, tin pest, particle accelerators, and atomic-level physical structures 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 There are more engineers today than any other time in history, inventing things daily. The pace of innovation is speeding up. Most people can’t keep up with all of it, and it’s difficult to understand its effects. From a Reliability Engineering perspective, new technology means new ways that things fail. The pace of things failing quadruples the pace of innovation. Plus, these failures are application specific. This means job security in the field of reliability! Reliability Engineering is an important part of innovation. The more effective we are at finding failures and understanding how these new technologies may fail, the better the inventions will be. We can explore these new innovations with wonder: How does this new thing NOT work? What are all the new ways things could fail? Fred and Dianna suggest filling a news feed with these technological advances and subscribing to news releases from sources you’re interested in. They started the conversation talking about the fusion reaction news that came from the Lawrence Livermore National Laboratory: www.llnt.gov/news. What are sources you follow for innovation news? Related Topics SOR 301 Working with Suppliers Offering New Technologies The post SOR 829 New Ways to Break Things appeared first on Accendo Reliability.

New School Leadership Abstract Chris and Fred discuss the changing ideas of leadership … and how people lament newer generations and their approaches to (and expectations of) leadership. There are challenges … so what does this mean? Key Points Join Chris and Fred as they discuss what appears to be many cultural clashes between old approaches to leadership and newer generations’ ideas of what good leadership looks like. What does this mean? Can it be good? Topics include: History lesson #1 – Japan and World War II. Japan’s entire culture/society changed entirely after World War II. Out was a traditional monarchist ruling class. In was a ‘technocracy’ where government officials were in charge of (and experts in) creating specific industries and skill sets. And this thing called the ‘Japanese Economic Miracle’ started. What about COVID? Before Covid, many leaders resisted flexible or ‘work from home’ conditions. Then Covid came. And many organizations quickly adapted. There are plenty of examples of companies that did not. There are plenty of examples of ‘critical events’ forcing organizations to change how they operate … and quickly dispelling myths that were previously seen as facts. … and reliability? Making reliability usually means a cultural change. Which needs leadership. And it also needs challenging myths that are currently perceived as facts. 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 Related Topics SOR 275 What is Reliability Leadership?(Opens podcast in a new browser tab)   The post SOR 828 New School Leadership appeared first on Accendo Reliability.

60th Percentile with Vendor Data Abstract What does this title mean? Chris and Fred discuss how some vendors make ‘startling’ claims regarding reliability from some small amounts of test data. So where does this 60th percentile some of us hear from time to time come from? Key Points Join Chris and Fred as they discuss some of the statistical gymnastics vendors go through to make certain claims about component reliability from ‘really’ small tests. How do we deal with vendors who make claims? Topics include: What is out there? There is a method (that we won’t go into here) where if we test something and observe zero failures, we then assume that a failure is imminent (i.e. a failure was going to occur the moment we stopped testing) and then we assume a constant hazard rate, and we can then come up with a 60th percentile lower confidence bound on the MTBF. This is awful. Frequentist versus Bayesian. Oh dear … here come the statistics. Most textbooks rely on the frequentist (or classical) school of statistics. That is … there is no information beyond that contained in the data. We make no assumptions. We have no previous knowledge. However … most ‘frequentist’ analyses involve prior knowledge or assumptions. Like the one above … where we assumed that a ‘failure is imminent.’ So what do we do #1? Start with understanding the DECISION. Let’s say the component in question is a relatively ‘well-known’ component in terms of how it fails, robustness and so on … then do we really need to know more about it’s reliability? If there are other components that are new, developmental, or otherwise problematic … then you don’t. However, if this component is ‘centrally important’ to the reliability of your system … and the only data you have is a vendor’s test (which you didn’t observe or be part of) with no failures observed? If this is not important to you … then neither is reliability. So what do we do #2? If there is no scope for testing or simulation regarding the reliability of your main component … then you can’t wish the problem away. If the component in question is (for example) a capacitor … then free research should help you work out how it might fail. Do we need to put in a clean power supply? … ESD protection? … or something else that will protect the functionality of this very important component for which you have no ‘statistical’ understanding of its reliability. 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 Related Topics Asking a Vendor for Reliability Data(Opens podcast in a new browser tab) SOR 611 Vendor MTBF Claim(Opens podcast in a new browser tab)   The post SOR 827 60th Percentile with Vendor Data appeared first on Accendo Reliability.

Reliability and Statistics Abstract Kirk and Fred discussing the use of statistics in reliability engineering,  where they are useful and where their use may not be the most efficient way to find and fix the cause of failure. Key Points Join Kirk and Fred as they discuss their different viewpoints on the use of statistics for reliability engineering. Topics include: Statistics has an important role in the design and manufacturing of electronics and systems. W. Edwards Deming, PhD. showed how using statistical process control (SPC) in manufacturing would reduce variations that can lead to field failures. Statistics are useful for distributions and life estimates for intrinsic wear-out mechanisms such as the need to determine the degradation of solar PV arrays and the estimate useful life. Fred recalls a time when he showed a client how statistics of having a spare unit for swapping out for a failing critical sensor in a critical Air Force surveillance system could save a mission, but that they still never corrected the cause of the failure to prevent needing the extra spare. Counting when and how many products fail in the field isn’t the best way to find how to make a more reliable product. Doing detailed failure analysis and determining the root cause of failures is the way to increase reliability. Statistics clearly has a use in making reliability long lasting systems, but failure analysis to root cause  is critical to understanding “unreliability” and how to prevent it. 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 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. Related Topics SOR 632 Statistics and Reliability(Opens podcast in a new browser tab)   The post SOR 826 Reliability and Statistics appeared first on Accendo Reliability.

Learning about Failures Abstract Kirk and Fred discussing the idea of listing of failure mechanisms and their different viewpoints on how we learn some of the common failure mechanisms Key Points Join Kirk and Fred as they discuss the challenge of listing potential failure mechanisms that usually occur when some mistake has been made in the design or manufacturing at some point in the supplier chain of materials and components. Topics include: Discussing how a chip assembly process has lead to mismatch of thermal coefficient of expansion (TCE) between the lead frame and encapsulation epoxy when the epoxy formula is not correct, and this has resulted IC package failures Many if not most field failures are a result of a combination of multiple chemical and mechanical mechanisms, and the interactions of those mechanisms and the end use environment makes it difficult to document and record the root cause or make a glossary of failure mechanisms. Technology development keeps changing the potential failure mechanisms that will have to be discovered from experience of building it and finding the new mechanism,After it is discovered it can be documented and prevented in future designs, but it is always like the “Whack-a-mole” arcade game where we never know where the next failure will come from. 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 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. Related Topics SOR 705 What is the Failure Mechanism(Opens podcast in a new browser tab) The post SOR 825 Learning about Failures appeared first on Accendo Reliability.