Guide: Failure Modes and Effect Analysis (FMEA)
- Last Updated: June 6, 2023
Failure Mode and Effects Analysis (FMEA) is a structured methodology used to identify and mitigate risks caused by system or process failures.
With this guide we will explain how to identify failure modes, assess their severity, determine causes and effects, estimate occurrence, evaluate existing controls, calculate Risk Priority Numbers (RPNs), develop action plans, and monitor and review the effectiveness of implemented measures, beginning with defining the scope and assembling a cross-functional team.
Table of Contents
FMEA is a systematic and proactive risk management technique for identifying and mitigating potential system, process, or product failures. The technique is widely used across industries to analyze potential failure modes, their causes, and their effects on overall operation. FMEA allows businesses to prioritize and address the most critical risks by assessing the severity, occurrence likelihood, and detectability of each failure mode. FMEA can also help businesses improve product quality, reliability, and safety by implementing targeted actions to prevent or reduce the impact of failures.
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Types of FMEA:
Design FMEA (DFMEA):
- Targets potential failures in product design.
- Ensures that products meet design and functional specifications.
Process FMEA (PFMEA):
- Examines the manufacturing and assembly processes.
- Aims to identify and correct potential process-related failures.
System FMEA (SFMEA):
- Analyze the entire system’s potential vulnerabilities.
- Ensures that all components of a system work harmoniously, preventing system-wide failures.
These three types of FMEA offer an approach to risk management at various stages of product development and system integration.
Step-by-Step Guide to Performing FMEA (With Examples)
Step 1: Assemble a Cross-Functional Team
The complexity of most processes, products, or systems often means that no single person has a complete understanding of all aspects. Therefore, a cross-functional team brings together different perspectives and expertise, leading to a more complete analysis.
How to Implement:
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- Identify key stakeholders and experts from various relevant departments.
- Include representatives from design, engineering, quality assurance, operations, and any other relevant department.
- Choose a team leader, preferably someone experienced with FMEA, to guide the process and ensure it stays on track.
- Ensure that team members are trained on the basics of FMEA so everyone starts with a foundational understanding.
Step 2: Define the Scope
To ensure that the FMEA remains focused and manageable, it’s crucial to clearly define what will be analyzed. This prevents the process from becoming too broad or overlooking critical areas.
How to Implement:
- Determine if the FMEA will focus on a product, a process, or an entire system.
- Define boundaries by clarifying what is included and what isn’t. For instance, if analyzing a manufacturing process, decide which specific stages or components will be the subject of the FMEA.
- Document any known assumptions or constraints that could influence the analysis.
Step 3: List Potential Failure Modes
At this stage, the goal is to identify all the potential ways the subject (be it a process, product, or system) might fail. This is the foundation of the FMEA, as understanding these failure modes is key to addressing them.
How to Implement:
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- Conduct brainstorming sessions with the cross-functional team to list potential failures. Encourage open communication and ensure every idea is considered without immediate judgment.
- Review past data, including incident reports, customer feedback, or warranty claims, to identify historical failure modes.
- For products or systems, consider using techniques like fault tree analysis or component testing to identify potential failure modes.
- Document each failure mode with a clear description. For instance, instead of just noting “motor failure,” specify “motor overheating leading to failure.”
Step 4: Evaluate the Potential Failure Effects, Potential Causes, and Current Controls
This step aims to further break down each identified failure mode by understanding its impact, root causes, and existing preventive measures.
How to Implement:
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- Potential Failure Effects: Determine what the consequences of each failure mode are. This can range from minor inconveniences to safety hazards.
- Potential Causes: Identify the root causes leading to the failure mode. This is essential for preventive action.
- Current Controls: Determine existing processes or measures that are in place to either detect or prevent the failure mode from occurring.
Step 5: Evaluate Severity, Occurrence, and Detection
The aim here is to quantify the risk associated with each failure mode. These three criteria help in understanding the magnitude of the problem and in prioritizing corrective actions.
How to Implement:
- Severity (S): Rate the seriousness of the consequences if the failure occurs. Typically rated on a scale of 1 (least severe) to 10 (most severe).
- Occurrence (O): Assess the likelihood of the failure mode occurring. Again, this is usually on a scale of 1 (least likely) to 10 (most likely).
- Detection (D): Evaluate the likelihood that the current controls will detect the failure mode before it reaches the end customer. This is rated on a scale where 1 means it’s very likely to be detected and 10 means it’s very unlikely.
- Note: You can find the full classification of scoring within our FMEA Template.
Step 6: Calculate RPN and Prioritize
The Risk Priority Number (RPN) provides a numerical value that represents the overall risk of each failure mode. It helps in prioritizing which failure modes should be addressed first.
How to Implement:
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Calculate RPN: For each failure mode, multiply the Severity, Occurrence, and Detection ratings:
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Prioritize: Once RPN values are calculated for all failure modes, sort them in descending order. Those with the highest RPNs should be given priority for corrective action since they represent the highest risk.
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Step 7: Develop Action Plans
The aim of this step is to design and plan corrective actions for the identified failure modes, particularly those with the highest RPN values. Addressing these failure modes will have the most significant impact on improving the process or product.
How to Implement:
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- Prioritize Failure Modes: Start by focusing on the failure modes with the highest RPNs. These represent the highest risks and should be addressed first.
- Brainstorm Solutions: Convene the cross-functional team to brainstorm potential solutions to the identified failure modes. Consider redesigning the process, adding inspections, or implementing new technologies.
- Assign Responsibility: For each action item, assign a responsible person or team. This ensures accountability and clarity on who will drive the corrective action.
- Set Deadlines: Establish a timeline for implementing the corrective actions. This helps in tracking progress and ensuring timely completion.
- Document Everything: Maintain a detailed record of the planned actions, responsibilities, and timelines. This documentation is vital for tracking progress and future audits.
Step 8: Implement and Monitor
After developing action plans, this step ensures that the corrective measures are put into practice and that their effectiveness is monitored over time.
How to Implement:
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- Execute the Action Plans: Implement the corrective actions as planned. This might involve training staff, purchasing new equipment, redesigning processes, or any other required change.
- Monitor Continuously: Regularly check the effectiveness of the implemented actions. Use metrics, inspections, or tests to evaluate whether the corrective actions are reducing or eliminating the failure modes.
- Feedback Loop: Create a feedback mechanism where frontline staff can report on the effectiveness of the corrective actions. Their insights are invaluable as they work directly with the process or product.
- Adjust as Necessary: If a corrective action isn’t yielding the desired results, don’t hesitate to modify it or try a different approach.
- Update FMEA: As corrective actions are implemented and processes change, the FMEA should be updated to reflect the current state. This might lead to changes in RPN values and further refinements.
- Celebrate Successes: Recognize and celebrate when corrective actions lead to significant improvements. This fosters a positive culture of continuous improvement.
FMEA Template
To support you with your FMEA implementation feel free to download our free FMEA template from the template section.
Conclusion:
FMEA is a useful tool that allows businesses to identify, assess, and address potential failures in processes, products, or systems.
By systematically evaluating each failure mode’s severity, occurrence, and detection, teams can quantify risks and prioritize corrective actions. Our guide walked through the essential steps of FMEA, from assembling a cross-functional team to calculating the RPN. We also illustrated the process with a tangible example from the plastic water bottle manufacturing industry.
References
- Mikulak, R.J., McDermott, R. and Beauregard, M., 2017. The basics of FMEA. CRC press.
- Lipol, L.S. and Haq, J., 2011. Risk analysis method: FMEA/FMECA in the organizations. International Journal of Basic & Applied Sciences, 11(5), pp.74-82.
A: FMEA stands for Failure Mode and Effects Analysis.
A: FMEA is a systematic and proactive method used to identify and analyze potential failures, their causes, and their effects in a system, product, or process.
A: Using FMEA offers several benefits, including:
- Early identification and prevention of potential failures
- Improved product or process design by addressing failure risks
- Enhanced product reliability and safety
- Reduction in costs associated with failures and rework
- Increased customer satisfaction through improved quality
A: The key steps in conducting an FMEA are as follows:
- Select the system, product, or process to be analyzed.
- Assemble a multidisciplinary team.
- Identify potential failure modes and their causes.
- Evaluate the severity, occurrence, and detection of each failure mode.
- Calculate a Risk Priority Number (RPN) to prioritize failure modes.
- Develop and implement actions to reduce or eliminate high-risk failure modes.
- Monitor and review the effectiveness of the actions taken.
A: The Risk Priority Number (RPN) is a numerical value calculated by multiplying the severity, occurrence, and detection rankings assigned to each failure mode during the FMEA process. It is used to prioritize failure modes for further analysis and action.
A: Yes, FMEA can be applied to various industries and fields, including manufacturing, healthcare, automotive, aerospace, software development, and many others. It is a versatile tool for risk assessment and mitigation.
A: Yes, there are different types of FMEA, including:
- System FMEA (SFMEA): Analyzes failures at the system level.
- Design FMEA (DFMEA): Focuses on failures associated with product design.
- Process FMEA (PFMEA): Analyzes failures in manufacturing or process operations.
- Software FMEA (SWFMEA): Specifically addresses failures in software development.
Author
Daniel Croft
Daniel Croft is a seasoned continuous improvement manager with a Black Belt in Lean Six Sigma. With over 10 years of real-world application experience across diverse sectors, Daniel has a passion for optimizing processes and fostering a culture of efficiency. He's not just a practitioner but also an avid learner, constantly seeking to expand his knowledge. Outside of his professional life, Daniel has a keen Investing, statistics and knowledge-sharing, which led him to create the website learnleansigma.com, a platform dedicated to Lean Six Sigma and process improvement insights.
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