Identify Functions and Failure Modes : Set up the DFMEA hierarchy by linking system functions and documenting failure modes, effects, and root causes within the risksheet 3-level structure. Score Severity, Occurrence, and Detection (RPN) : Assign severity, occurrence, and detection ratings to compute the pre-mitigation Risk Priority Number for each failure mode. Add DFMEA Risk Mitigation Actions : Create and link mitigation tasks to failure modes, track their status, and verify requirements traceability through the risksheet. Evaluate Post-Mitigation RPN : Re-score occurrence and detection after mitigation actions to compute the post-mitigation RPN and confirm risk reduction effectiveness.
DFMEA vs. HARA
The Medical Device Safety Solution uses a dual risk methodology where DFMEA and HARA serve complementary purposes:| Aspect | DFMEA | HARA |
|---|---|---|
| Focus | How functions fail (design perspective) | How hazards harm users (safety perspective) |
| Hierarchy | Function > Failure Mode > Cause | Use Step > Hazard > Situation > Harm |
| Scoring | S x O x D = RPN (numeric) | P1 x P2 x Severity = Risk Level (categorical) |
| Traceability | Links to HARA risk records via analyzedIn | Links to DFMEA failure modes via cause column |
Document Structure
DFMEA documents are organized in a system-subsystem hierarchy within theRisks/ space:
| Document | Level | Content |
|---|---|---|
| FMEA-SYS-001 | System | 34 failure modes for the full device |
| DFMEA-SUB-001 through SUB-006 | Subsystem | 13-15 failure modes each, scoped to a component |
Related Resources
- Dual Risk Methodology: HARA and DFMEA — understand when to use each method
- DFMEA Risksheet Configuration Reference — column definitions and formula details
- Failure Mode (failureMode) — work item type reference
- HARA Analysis Workflows — companion HARA analysis guides