TL;DR
FMEA (Failure Modes and Effects Analysis) identifies potential failure points before they happen.
In Six Sigma, it's primarily used during the Measure and Analyze phases.
FMEA ranks risks based on Severity, Occurrence, and Detection to prioritize action.
Real-world application: reduces defects, improves safety, and saves costs.
Best used alongside tools like Fishbone Diagrams and Control Plans for robust results.
What is FMEA in the Six Sigma Process?
Failure Modes and Effects Analysis (FMEA) is a structured, proactive tool used to identify where and how a process might fail and assess the relative impact of different failures. Within the Six Sigma methodology, FMEA plays a critical role, especially during the Measure and Analyze phases of the DMAIC framework.
By systematically evaluating potential failure modes, teams can prioritize the most significant risks and develop mitigation strategies early before costly problems occur.
FMEA focuses on three key factors:
Severity (S): How serious are the consequences?
Occurrence (O): How likely is it to happen?
Detection (D): How likely is it that the issue will be caught before it impacts the customer?
Each factor is rated on a scale (usually 1–10), and their product (S × O × D) gives the Risk Priority Number (RPN).
Organizations using proactive risk assessment tools like FMEA can improve product reliability by up to 40%.
How to Perform FMEA in a Six Sigma Project
Effective use of FMEA requires a systematic approach. Here's how it's typically executed in a Six Sigma project:
Step 1: Map the Process Start by breaking down the process into individual steps. Each step becomes a candidate for potential failure.
Step 2: Identify Failure Modes List all the ways each step could go wrong. Failure modes could include machine breakdowns, human errors, material defects, or software bugs.
Step 3: Evaluate Severity, Occurrence, and Detection Assign scores for each failure mode based on how severe it is, how often it might occur, and how easily it can be detected.
Step 4: Calculate the RPN Multiply Severity, Occurrence, and Detection ratings to find the Risk Priority Number. Higher RPNs indicate higher risk areas.
Step 5: Prioritize and Act Focus efforts on failure modes with the highest RPNs. Develop action plans to eliminate, reduce, or detect these failures earlier.
Example: A Six Sigma team at an automotive company used FMEA to assess risks in an airbag deployment system. They discovered that a minor wiring defect (previously overlooked) had a high severity and occurrence rating, prompting a redesign that averted potential recalls.
Fun Fact: The U.S. Department of Defense originally developed FMEA in the 1940s to improve military systems reliability, according to NASA (source).
Benefits of Using FMEA in the Six Sigma Process
When applied properly, FMEA offers tangible improvements across quality, safety, and cost-efficiency metrics:
1. Early Risk Detection Identifying problems before they escalate prevents costly delays and rework.
2. Data-Driven Decision Making FMEA quantifies risks, making it easier for teams to prioritize improvements objectively rather than by gut feeling.
3. Enhanced Customer Satisfaction By addressing issues before product release, organizations deliver more reliable, higher-quality offerings.
4. Regulatory Compliance Industries like automotive (IATF 16949) and healthcare (FDA) often require documented risk assessments like FMEA.
Example: A medical device manufacturer integrated FMEA into their Six Sigma program and reduced device failure rates by 35%, significantly boosting regulatory audit scores.
For a full toolkit of Six Sigma methodologies to complement FMEA, visit The Ultimate Guide to Six Sigma: Everything You Need to Know.
Bonus: A McKinsey report notes that early risk identification can reduce product launch delays by up to 25% (source).
Real-World FMEA Application in Six Sigma Projects
Let's look at how FMEA fits into an actual Six Sigma DMAIC project:
Problem: Excessive warranty claims for a home appliance manufacturer.
Six Sigma DMAIC Application:
Define: Warranty claims on refrigerators have increased by 20%.
Measure: Identify that the compressor unit is the frequent failure point.
Analyze: Conduct FMEA on the compressor assembly process.
Findings:
Severity: High (customer inconvenience)
Occurrence: Medium (common supplier issue)
Detection: Low (quality checks missing)
High RPN flagged "substandard compressor seals" as the top failure mode. The team switched to a more robust sealing supplier and added a pressure test at assembly.
Result: Warranty claims dropped by 50% in the next 12 months.
This case highlights why integrating FMEA during the Six Sigma process isn't just best practice it's critical to success.
