Skip to main content

​
Overview

Defining failure modes is the foundation of FMEA analysis. A failure mode describes how a system element, function, characteristic, or process step can fail to meet its intended purpose. Proper failure mode definition determines the quality of your entire risk assessment.

​
Step 1: Navigate to Your FMEA Document

  1. Open the Risks space from the main navigation
  2. Locate your FMEA document (System FMEA, Design FMEA, or Process FMEA)
  3. Click the document title to open the risksheet view
You should see the progressive workflow view structure with columns for failure mode identification.

​
Step 2: Understand the FMEA Hierarchy

Each FMEA type uses a different three-level hierarchy:
FMEA TypeLevel 1 (Item)Level 2 (Failure)Level 3 (Root Cause)
System FMEACustomer RequirementFailure Mode (failureMode)Cause (riskRecord)
Design FMEAFunction or CharacteristicFailure Mode (failureMode)Cause (riskRecord)
Process FMEAProcess StepProcess Failure Mode (processFailureMode)Cause (riskRecord)
The AIAG-VDA FMEA methodology supports analyzing both functions (what the system does) and characteristics (measurable attributes). Choose based on your analysis focus — functional for early design stages, characteristic-based for detailed design verification.

​
Step 3: Add a Failure Mode Row

  1. For System/Design FMEA: Select the parent item (customer requirement, function, or characteristic) in the risksheet
  2. For Process FMEA: Select the process step you’re analyzing
  3. Click the Add Child button or right-click and select New Work Item
  4. Choose work item type:
    • failureMode for System FMEA and Design FMEA
    • processFailureMode for Process FMEA
  5. The new row appears nested under the parent item

​
Step 4: Document the Failure Mode

Fill in the core failure mode fields:
FieldDescriptionExample
TitleBrief description of how the item fails”Brake pedal fails to activate brake lights”
Effect of FailureWhat happens when this failure occurs”Following driver cannot see braking, rear collision risk”
Cause of FailureWhy this failure might occur”Brake light switch malfunction or wiring fault”
Failure Mode = HOW the item fails (e.g., “Motor does not start”)
Cause = WHY it fails (e.g., “Corroded electrical connector”)
Effect = WHAT happens as a result (e.g., “Vehicle immobilized”)Keep these concepts distinct to enable proper risk assessment.
Depending on your FMEA type, establish the correct relationships: System FMEA:
  • Ensure the failure mode is nested under the correct customer requirement
  • No additional links required at this stage
Design FMEA:
  • Use the Assesses link role to connect the failure mode to the function or characteristic being analyzed
  • This relationship enables PowerSheet traceability views to show which design elements have FMEA coverage
Process FMEA:
  • Process failure modes automatically inherit the parent process step context
  • Link to downstream control plan items if already defined

​
Step 6: Add Multiple Failure Modes

For comprehensive analysis, identify multiple failure modes per analyzed item: Function: “Illuminate brake lights when pedal pressed” ├─ FM1: Brake lights fail to illuminate ├─ FM2: Brake lights illuminate with delay ├─ FM3: Brake lights remain illuminated continuously └─ FM4: Only partial brake lights illuminate Repeat steps 3-5 for each distinct failure mode. Aim for completeness rather than speed — missed failure modes represent unanalyzed risks.
Use systematic approaches to ensure completeness:
  • Function negation: “What if this function doesn’t happen, happens partially, or happens at the wrong time?”
  • Historical data: Review warranty claims, field failures, and test defects
  • STRIDE analysis: Consider Spoofing, Tampering, Repudiation, Information disclosure, Denial of service, Elevation of privilege (for software functions)

​
Step 7: Document Severity Rating

For each failure mode, assign the Severity rating (1-10 scale):
  1. Locate the fmSeverity column in your risksheet view
  2. Select the appropriate severity value based on the effect of failure
  3. Reference the FMEA Severity enumeration for rating criteria
Severity reflects the inherent seriousness of the effect if the failure occurs. It remains constant even after adding risk controls. Only Occurrence and Detection ratings change pre/post mitigation.

​
Verification

You should now see:
  • Failure mode rows nested under the correct parent items
  • Title, effect, and cause fields populated with clear descriptions
  • Severity ratings assigned for all failure modes
  • No leaked “Undetermined” default values in core fields
The failure modes are now ready for the next FMEA workflow steps: occurrence and detection rating, action priority calculation, and risk control planning.

​
See Also