A failure mode and effects analysis, commonly known as FMEA, is a way to analyze the different ways a system, design, machine, component, process, product, or service can fail and the effects of those different potential failures.
The FMEA is recorded on an FMEA worksheet.
We’ll explain more about this technique commonly used in many industries in this introductory article. Stay tuned in the future, as we’ll probably also create a free downloadable FMEA worksheet for you.
History and Current Use of FMEA
The failure modes and effects analysis was originally developed by the United States military in the 1940s (this means that FMEA is like lean manufacturing in having its roots in the US military, as we described in our article on the lean predecessor TWI). After that, FMEA or variants were picked up and used by NASA, the aviation industry, and the automotive industry, offshore oil exploration, as well as others. Today, it’s widely used in many industries, including processing semiconductors, food service, plastics, healthcare, and software.
Is the FMEA Used Before Failures or After?
You can perform an FMEA before an accident or incident occurs or after (so it serves as something like an incident investigation).
Of course, the benefit of perform a failure mode and effects analysis before an accident occurs to contribute to your risk management efforts.
Consider performing an FMEA:
- While designing or redesigning a process, product, or service
- Before applying a process, product, or service in a new or unusual way
- While trying to improve an existing process, product, or service
- During analysis of a failure, accident, or incident
- On a periodic basis for existing processes, products, or services
How to Perform an FMEA
There’s no one single way to perform an FMEA that’s universally adopted, but here’s one example FMEA procedure. You can follow this procedure while performing a failures modes and effects analysis at your workplace or modify it for your own specific needs. You may also want to investigate if their are specific standards or best practices for performing an FMEA in your industry.
- Create a diverse team of people from different departments with different knowledge sets about the process, product, service, etc. that will be the focus of your FMEA. Be sure to include frontline employees and people with knowledge of customer needs/voice of the customer. Include people from design, operations, quality, maintenance, reliability, purchasing, sales, marketing, and customer service, if possible.
- Define the scope of your FMEA. Determine what you are investigating, the boundaries of the investigation, and the desired level of detail. Illustrate this in flowcharts and share with team members.
- Complete the introductory information in your FMEA form, which includes the name of the process/product/system you’re analyzing and similar “introductory” information.
- Define the function of the thing you’re analyzing with your FMEA. Explain its purpose and what customers expect of it. Break this down to cover smaller subsystems, components, etc.
- For each function, create a list of all the different ways it could fail. These are your failure modes.
- For every failure more, list the potential consequences of that failure. Ask what happens in each of these failures and how the customer would be affected. These are your effects.
- Rate the severity of the effects of the different failures on a scale of 1-10 (one is less severe, 10 is more severe). The severity rating is known as S.
- For every failure mode, try to list all potential causes of that failure.
- For every cause of a failure, rate the probability that the cause might lead to a failure during the lifetime of your project scope. Rate the probability on a scale of 1-10, with 1 being low probability and 10 being a certainty. This is sometimes known as the occurrence rating (because it’s a rating of the probability that the failure will occur). The occurrence rating is known as O.
- For every cause, identify process controls, including things like tests, procedures, guards, or other mechanisms, that you currently have in place. This can include things from preventing the cause from occurring, reducing the probability the cause will occur, and/or to detect that the cause did occur and prevent the affected product from reaching the customer.
- For each of those process controls, determine a detection rating, which is an estimate of how well the control can prevent the failure from affecting a customer. Rate this on a scale of 1-10, with 1 meaning you’re certain it will detect the problem and 10 meaning you’re certain it will not. The detection rating is known as D.
- In specific industries, you’ll want to determine if a failure is associated with a critical characteristic. A critical characteristic is a measurement or other indicator that relates to safety or compliance with a government regulation and that therefore requires additional controls. If so, and if special controls are required, write Y for yes in a column titled “classification” and if not, write N for no.
- Multiply the severity rating, S, by the occurrence rating, O, by the detection rating, D, to determine your risk priority number, or RPN.
- Multiple the severity rating, S, by the occurrence rating, O, to determine criticality.
- Use your risk priority numbers, RPN, and criticality ratings to prioritize the potential failures in the order in which you should address them.
- Identify and list recommended actions for each potential failure in the order you’ve just determined with the goal of lowering severity (S) or occurrence (O).
- Identify who’s responsible for completing each action and when the action should be completed.
- Note when actions are completed, results, and date on the FMEA form, and note the new/revised severity (S), occurrence (O), and detection (D) ratings as well as the new risk priority numbers (RPN).
Conclusion: The Failure Modes & Effects Analysis is a Great Risk Management & Process Improvement Technique
We hope you enjoyed this introduction to the failure modes and effects analysis (FMEA) and hope it helps you mitigate risks and avoid failures and accidents at your workplace.
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