Failure Mode and Effects Analysis (FMEA)

Failure Mode and Effects Analysis (FMEA)

What is FMEA?

FMEA is a systematic, proactive method for evaluating a process to identify where and how it might fail and to assess the relative impact of different failures.

Types of FMEA

Design FMEA (DFMEA)

Focuses on potential design weaknesses

• Component failures
• System interactions
• Design specifications

Process FMEA (PFMEA)

Focuses on process failures

• Manufacturing/operational processes
• Service delivery
• Administrative procedures

System FMEA

Focuses on system-level failures

• System functions
• Subsystem interactions
• Interface failures

FMEA Process

Step 1: Identify Functions

List all functions of the process/product

Step 2: Identify Potential Failure Modes

For each function, how could it fail?

• Complete failure
• Partial failure
• Intermittent failure
• Degraded function

Step 3: Determine Effects

What happens if each failure occurs?

• Local effects
• System effects
• End user effects

Step 4: Identify Causes

What could cause each failure mode?

• Root cause analysis
• Multiple causes possible

Step 5: Assess Current Controls

What controls exist to prevent/detect?

• Prevention controls
• Detection controls
• Current effectiveness

Step 6: Calculate Risk Priority Number (RPN)

RPN = Severity × Occurrence × Detection

| Rating | Severity | Occurrence | Detection | |--------|----------|------------|-----------| | 1 | None | Very rare | Almost certain | | 5 | Moderate | Occasional | Moderate | | 10 | Hazardous | Very high | No detection |

Step 7: Prioritize and Act

• Focus on highest RPNs
• Develop action plans
• Assign responsibilities
• Track to completion

Step 8: Recalculate RPN

After implementing actions, reassess to confirm improvement

FMEA Worksheet Columns

1. Item/Function
2. Potential Failure Mode
3. Potential Effect(s)
4. Severity (S)
5. Potential Cause(s)
6. Occurrence (O)
7. Current Controls
8. Detection (D)
9. RPN (S×O×D)
10. Recommended Actions
11. Responsibility/Target Date
12. Actions Taken
13. Revised RPN

Best Practices

• Cross-functional team
• Start early in design/planning
• Use lessons learned from past failures
• Update regularly
• Link to continuous improvement