Failure Mode Effects Analysis

Understanding FMEA methodology:

What FMEA Does:
- Identifies potential failure modes
- Assesses severity, occurrence, and detection
- Prioritizes risks for action
- Documents preventive actions
- Creates living risk documentation

Key Terms:

Failure Mode:
The way something can fail:
- What goes wrong?
- How does it fail to perform?
- Examples: breaks, corrodes, sticks, leaks

Effect:
The consequence of failure:
- What happens when it fails?
- Impact on customer/next operation
- Safety implications

Cause:
Why the failure occurs:
- Root cause mechanism
- Process or design deficiency
- What enables the failure?

Controls:
Current prevention and detection:
- Design features preventing failure
- Process controls
- Inspection and testing

Types of FMEA:

Design FMEA (DFMEA):
- Analyzes product design
- Before design release
- Focuses on design adequacy
- What if this component fails?

Process FMEA (PFMEA):
- Analyzes manufacturing process
- Before production start
- Focuses on process capability
- What if this process step fails?

System FMEA:
- Higher level, system interactions
- Interface and integration failures
- Less common but valuable

When to Conduct FMEA:
- New product/process development
- Design or process changes
- New applications of existing designs
- After quality problems occur
- Regular review and update

Evaluating and ranking risks:

Severity (S):
How bad if failure occurs:

Rating Scale (1-10):
- 10: Safety hazard without warning
- 9: Safety hazard with warning
- 8: Major function loss
- 7: Reduced function
- 5-6: Performance degradation
- 3-4: Minor effect
- 1-2: No noticeable effect

Industry-specific scales exist (AIAG, etc.)

Occurrence (O):
How likely is the cause to occur:

Rating Scale (1-10):
- 10: Failure almost certain
- 9: Very high probability
- 7-8: High probability
- 5-6: Moderate probability
- 3-4: Low probability
- 1-2: Very unlikely

Based on historical data when available

Detection (D):
How likely current controls will detect:

Rating Scale (1-10):
- 10: Cannot detect (no control)
- 9: Very unlikely to detect
- 7-8: Low detection probability
- 5-6: Moderate detection probability
- 3-4: High detection probability
- 1-2: Almost certain detection

Higher number = worse detection

Risk Priority Number (RPN):
Traditional prioritization:
RPN = Severity x Occurrence x Detection
Range: 1 to 1000

Limitations of RPN:
- Same RPN, very different risks
- Severity often should dominate
- AP (Action Priority) now preferred

Action Priority (AP):
New AIAG-VDA approach:
- High (H): Must address
- Medium (M): Should address
- Low (L): May address
- Based on decision tables, not multiplication
- Severity gets appropriate weight

Step-by-step FMEA development:

Preparation:

Form the Team:
- Cross-functional representation
- Design, manufacturing, quality, service
- Subject matter experts
- Facilitator experienced in FMEA

Gather Information:
- Engineering drawings/specifications
- Process flow diagrams
- Similar product/process FMEAs
- Warranty and quality data
- Customer complaints

FMEA Execution:

Step 1: Define Scope
- Product/process boundaries
- Functions and requirements
- Interfaces with other systems

Step 2: Identify Functions
- What should product/process do?
- Performance requirements
- Customer expectations

Step 3: Identify Failure Modes
For each function:
- How can it fail to perform?
- Think negatives of function
- Include partial failures

Step 4: Identify Effects
For each failure mode:
- What is the consequence?
- Consider end customer impact
- Consider next operation impact

Step 5: Assign Severity
Rate the worst effect:
- Use consistent rating scale
- Focus on most severe effect
- Safety effects drive high ratings

Step 6: Identify Causes
For each failure mode:
- What enables this failure?
- Technical root cause
- May have multiple causes

Step 7: Assign Occurrence
Rate likelihood of cause:
- Based on history/data when possible
- Consider current prevention controls

Step 8: Identify Controls
Current prevention and detection:
- What prevents the cause?
- What detects the failure?

Step 9: Assign Detection
Rate detection capability:
- How likely to catch before customer?
- Consider all detection points

Step 10: Calculate Risk
RPN or Action Priority:
- Identify high-priority items
- Focus on actionable improvements

Step 11: Recommended Actions
Reduce risk through:
- Design changes (reduce severity)
- Process improvements (reduce occurrence)
- Better controls (improve detection)

Step 12: Document and Track
- Assign ownership and dates
- Track completion
- Update FMEA with results

FMEA expertise enhances career opportunities:

Quality Engineer:
Lead and participate in FMEAs:
- New product development teams
- Process FMEA development
- Customer issue response
- $65,000-$95,000

Design Engineer:
Incorporate FMEA in design process:
- DFMEA development
- Design for reliability
- Risk-based design decisions
- $70,000-$100,000

Process Engineer:
Manufacturing process FMEAs:
- PFMEA development
- Process validation
- Control plan development
- $70,000-$100,000

Reliability Engineer:
Advanced risk assessment:
- Complex FMEA facilitation
- Integration with reliability tools
- Warranty prediction
- $80,000-$120,000

Industry Requirements:

Automotive (IATF 16949):
- FMEA required for all new products/processes
- Customer-specific requirements
- AIAG-VDA FMEA handbook
- Strict documentation expectations

Medical Devices (FDA, ISO 14971):
- Risk management required
- FMEA as key tool
- Severity drives decisions
- Documentation critical

Aerospace (AS9100):
- Risk-based thinking
- FMEA common tool
- Product safety focus

Skills to Develop:

Technical:
- Product/process knowledge
- Failure modes understanding
- Statistical/historical data analysis

Facilitation:
- Lead cross-functional teams
- Drive productive discussion
- Manage conflict and consensus

Documentation:
- Clear, complete FMEAs
- Track actions to completion
- Maintain living documents

Training:
- AIAG-VDA FMEA training
- Company-specific training
- ASQ CRE for reliability focus

Mastering FMEA demonstrates proactive quality mindset valued across industries.