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A qualitative and systematic analysis method intended to identify, prioritize, and reduce technical risks of failures to an acceptable level, with emphasis on improving product design or manufacturing process. FMEA is a structured process used to identify and prioritize potential failure modes that should receive an appropriate level of mitigation (elimination, reduction, or prevention).
Many companies miss out on the value of System FMEA and begin with lower level sub-assemblies or components. This article explains why it is usually best to begin with a properly done System FMEA.
“Big whirls have little whirls,
That feed on their velocity;
And little whirls have lesser whirls,
And so on to viscosity.”
Lewis Fry Richardson
“Prediction is very difficult, especially if it’s about the future.” Niels Bohr
In an FMEA, is it possible to think of everything that might happen in the future? What strategies can be used by FMEA teams to maximize the opportunity to anticipate what can go wrong, so risk can be reduced to an acceptable level?
Equipment failure is a reality that cuts across every industry. And when it occurs, its impact can vary from minimal inconveniences with localized damages that are easily contained and repaired, to significant incidents with damaging effects on the environment accompanied by several health and safety implications.
Before commencing with the FMEA meetings, it is essential to visibly show the nature and scope of the analysis. This article discusses different ways FMEA scope can be made visible, and why this is a necessary step.
“The soul cannot think without a picture” – Aristotle
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…]
DFMEA’s definitely have a bad reputation as exercises that consume an enormous amount of time and unfortunately yield little value to the program.
And can be miserable to experience.
A quote from a customer “We aren’t going to do any more DFMEA’s because we feel a bit traumatized by the last round.”
I have also seen DFMEA’s be a cornerstone to a design program using its resources with surgical precision to improve the product.
I started to think about the differences between the ineffective and effective DFMEA’s. Here are some of the steps that I believe make the “good ones” GOOD. [Read more…]
Products and equipment start with a design. The functions and performance occur or do not occur according to the capabilities designed into the system.
I learned early in my career, as a manufacturing engineer, that some products were much easier to manufacture (less yield loss) than others, and it was often the design of the product that made the difference. [Read more…]
It is rare that a third party generated FMEA/FMECA has any value. The development or manufacturing teams and supporting staff should comprise the bulk of the study’s team. Team size for a specific study would include 4 to 10 individuals.
The FMEA/FMECA should provide clear action items that may include:
Conduct research or experiments to understand and quantify uncertainty. This may include exploring how an item responds to specific stress, errors or inputs. Or include experiments to estimate the occurrence rating for a specific potential cause of a failure mode. [Read more…]
Every failure provides information. It provides time to failure, stress strength relationship, process stability and design margin types of information. In every case. Even failures directly related to human error.
A hardware intermittent failure observed by a firmware engineer should not be dismissed. Rather recorded, explored and examined.
A single intermittent failure, or glitch, may indicate nothing other than just a totally random glitch, or a design error that degrades over time causing 50% of units to fail in first three months.
Failure modes and effect analysis is a tool to identify potential failures and prioritize based on severity, occurrence, and detection. I like to describe FMEA as an organized brainstorm. You probably have some experience with FMEA.
In some industries, there is a high expectation or mandate to do an FMEA study. In some industries FMEA maybe just another tool to consider using during various stages of the product or asset lifecycle.
In my opinion, FMEA should be a part of your project plan when it is likely to add value.
Value in the sense that the organization will receive an adequate benefit based on the investment to conduct the FMEA study. [Read more…]
In Chapter 8 of The Basics of FMEA by Robin E. McDermott, et. al. discusses the ten steps for an FMEA. I find it to be an excellent summary for describing and conducting a failure mode and effect analysis.
Therefore based on the work of McDermott and others, plus my own experience here are the ten steps with my descriptions. [Read more…]
Failure modes and effect analysis (FMEA) is a tool that works to prevent process and product problems before they occur.
I like to define FMEA’s as an organized brainstorm. The process examines a product or process and asks what could go wrong. Then the team systematically determines and rank orders for each failure mode:
– the severity of the problem when it occurs
– the probability of the problem occurring
– the ability to detect the problem before it occurs
Good design engineers think about how the design could fail and improve the design. FMEA provides a structured team approach to further improve the design.
Failure mode and effects analysis, or FMEA, is a tool for the identification and prioritization of possible ways a product or process can fail. The intent is to use that information to make improvements to the product or process.
I think of FMEA (and related processes like FMECA, dFMEA, etc.) as structured brainstorms that provide a means to focus on what’s important. [Read more…]
