The Planning and Preparation phase is the foundation of the AIAG-VDA DFMEA. It ensures that your risk analysis is focused, efficient, and aligned with product development timelines.
Most DFMEA failures happen not because of technical gaps, but due to:
- Unclear boundaries
- Missing cross-functional insights
- Poor timing
- Ignored interfaces
This lesson solves that by walking you through Step 1 using the 12V Electric Water Pump (EWP) as a case study.
🎯 Objective of Step 1 #
“Define the DFMEA scope, system boundaries, assumptions, interface list, project timing, and team composition to ensure an effective risk analysis process.”
🔍 Key Activities in Step 1 – Planning & Preparation #
| Activity | Purpose |
|---|---|
| Define Scope & Boundaries | Limit what the DFMEA will and won’t include |
| Identify Interfaces | Recognize all internal and external connections |
| State Assumptions | Clarify what is presumed to be true |
| Gather Inputs | Collect past DFMEAs, specifications, test plans, lessons learned |
| Define Timing | Align with program milestones and APQP gates |
| Build Cross-functional Team | Involve all relevant departments and roles |
| Document Planning Sheet | Record all planning info in a structured template |
🚗 Case Study: 12V Electric Water Pump (EWP) #
Let’s apply this to our EWP example:
🧱 Scope Definition
The DFMEA covers:
- EWP assembly including impeller, shaft, BLDC motor, PCB, connector, and housing
- Operating range: 9–16V, −40°C to 125°C
- Functions: Flow delivery, thermal control, EMC, sealing
It excludes:
- External coolant hoses (owned by customer)
- Vehicle wiring harness and ECU (covered in separate DFMEA)
- Firmware logic (covered in SW-FMEA)
✅ Defined in scope document with version control.
🧊 Boundaries
| Boundary Type | Description |
|---|---|
| Physical | Starts at pump housing inlet → Ends at electrical connector |
| Functional | Includes signal processing, motor control, mechanical drive |
| Lifecycle | Includes manufacturing, transport, operation, service |
🔌 Interface Identification
Identify interfaces that can create failure risks if not handled properly.
| Interface Type | Example |
|---|---|
| Mechanical | Mounting to engine block, impeller-shaft press fit |
| Thermal | Coolant heat transfer, motor overheating |
| Electrical | 12V supply, ground, PWM signal line |
| Environmental | Dust/water ingress, coolant compatibility |
| Electromagnetic (EMC) | Radiated/conducted emissions, ECU noise immunity |
✅ Captured in Interface Matrix or ICD (Interface Control Document)
📋 Assumptions List
| Assumption | Justification |
|---|---|
| Coolant is OEM-approved glycol mix | Based on customer spec |
| Power supply is 12V ±20% | Aligned with battery spec |
| ECU sends valid PWM signals | Covered under ECU SW DFMEA |
| Pump operates intermittently, not continuously | Based on thermal load use case |
✅ Documented in the DFMEA cover sheet or planning notes
📥 Input Documents
| Input Type | Examples |
|---|---|
| Technical Specs | Flow rate, pressure, life, noise, voltage, EMC |
| CAD/BOM | 3D model, exploded view, part list |
| Previous DFMEAs | Water pump gen-1, oil pump, PCB DFMEA |
| Customer Requirements | RFQ spec, special characteristics |
| DVP&R (Draft) | Planned test methods and acceptance criteria |
| Lessons Learned | Seal leaks in dusty environments, EMI spikes on PWM line |
✅ Stored in central folder (e.g., SharePoint/PLM)
👥 Cross-functional Team (CFT)
| Role | Department | Responsibility |
|---|---|---|
| Design Engineer | Mechanical | Lead DFMEA creation |
| Electrical Engineer | EE | Circuit and layout risks |
| Software/Controls | Embedded SW | Signal logic clarification |
| Manufacturing | Assembly | Process feedback and feasibility |
| Quality Engineer | QMS | FMEA moderation and compliance |
| Testing Engineer | Validation | Support DVP & detection controls |
| System Engineer | Platform | Interface and system-level effects |
✅ RACI matrix can clarify who owns what
⏳ DFMEA Timing Plan
The DFMEA must align with your APQP timeline, usually between:
- Gate 1: Concept Freeze
- Gate 2: Design Freeze
- Gate 3: DV (Design Verification)
- Gate 4: PV (Production Validation)
- Gate 5: SOP (Start of Production)
🔄 Plan to update DFMEA after each gate or major change.
| Milestone | DFMEA Status |
|---|---|
| Gate 1 | Scope, structure, function complete |
| Gate 2 | Failure analysis, initial S-O-D ratings |
| Gate 3 | Optimization and actions updated |
| Gate 4 | Residual risk summary, sign-off |
| SOP | Frozen DFMEA linked to Control Plan & PPAP |
📑 Template Snapshot: DFMEA Planning Sheet #
Here’s what your DFMEA planning section might include:
| Field | Example Entry |
|---|---|
| DFMEA Item | 12V Electric Water Pump |
| Program | Cooling System Gen-3 |
| Prepared By | John Smith |
| Revision | Rev 1.2 |
| Scope Statement | Covers internal EWP assembly, electrical and sealing functions |
| Out of Scope | ECU logic, external harness |
| Interfaces Considered | Coolant, 12V power, PWM, EMC, mounting |
| Assumptions | Coolant is glycol-based, PWM duty provided by ECU |
| Timing | Aligned with APQP gates 1–5 |
| Team Members | [List of names and roles] |
📥 Download this as an editable Excel or PDF
🧠 Pro Tip #
“Don’t treat Step 1 as a formality. A well-scoped DFMEA saves time and ensures everyone is aligned on expectations, responsibilities, and risks.”
🧩 5T Questions – Applied to EWP DFMEA (AIAG-VDA Step 1) #
The 5T Method ensures clarity and alignment in the planning phase of DFMEA. These questions guide the team to think about the “what, why, when, who, and how” before diving into analysis.
Here’s how the 5Ts apply to our case study: the Electric Water Pump (EWP)
✅ 1. InTent – Why are we doing this analysis?
To ensure the design of the 12V Electric Water Pump meets all critical functional requirements, including:
- Delivering coolant flow on demand
- Operating reliably in thermal and vibration environments
- Meeting regulatory EMC, sealing, and durability criteria
- Preventing known field failures from past designs
This DFMEA supports customer-specific requirements, product safety, regulatory compliance, and zero-defect launch readiness.
✅ 2. Timing – When is the DFMEA being done?
The DFMEA is being initiated at the product concept/design phase, prior to design freeze, and aligns with:
| Milestone | Timing Goal |
|---|---|
| Gate 1 (Concept Freeze) | Complete scope, structure, functions |
| Gate 2 (Design Freeze) | Complete failure analysis and risk ratings |
| Gate 3 (DV Testing) | Implement and update actions |
| Gate 4 (PV Testing) | Close actions, summarize residual risk |
| Gate 5 (SOP) | Freeze DFMEA; link to Control Plan |
✅ 3. Team – Who is responsible for this analysis?
A cross-functional team (CFT) has been formed, including:
| Role | Responsibility |
|---|---|
| Design Engineer (Mech) | Structural design, impeller/shaft/seal interfaces |
| Electrical Engineer | Motor, PCB layout, circuit protection |
| Controls Engineer | PWM interface, Hall sensor logic |
| Quality Engineer (Moderator) | DFMEA facilitation and compliance |
| Validation/Test Engineer | Detection controls, test methods |
| Manufacturing Rep | DFM feedback and assembly process risks |
| Systems Engineer | Interface with ECU, thermal system, vehicle-level effects |
✅ 4. Task – What product or process are we analyzing?
Product:
12V Electric Water Pump used in ICE and hybrid vehicles for cooling system regulation.
Scope of Analysis Includes:
- Motor and mechanical drive
- Impeller and shaft/bearing system
- Seal and housing interfaces
- Electronics (PCB, Hall sensor, protection)
- Electrical connector
- Environmental protection features (sealing, coating)
Out of Scope:
- ECU software logic (covered in separate SW-FMEA)
- External hose connections
- Wire harness (customer-owned)
✅ 5. Tool – How will we document and structure the analysis?
We are using the AIAG-VDA DFMEA 7-Step methodology, documented using:
- 🧾 Excel-based DFMEA Template (AIAG-VDA aligned)
- 📊 Structure Tree and Function Block Diagram
- 📎 Interface Matrix and Assumption Log
- 📁 SharePoint for collaboration and version control
- 📅 MS Teams + recurring DFMEA review meetings
✅ Tool enables linkage to DVP&R, Control Plan, and Lessons Learned
✅ Summary Table – 5T Snapshot #
| T | Question | EWP DFMEA Answer |
|---|---|---|
| InTent | Why? | Ensure thermal performance, safety, EMC, durability |
| Timing | When? | Pre-design freeze through to SOP |
| Team | Who? | CFT with design, quality, electrical, test, manufacturing |
| Task | What? | Full EWP assembly and function scope |
| Tool | How? | AIAG-VDA 7-Step in Excel + DVP&R integration |
✅ Tip for Learners:
Never skip the 5T discussion in Step 1. It aligns expectations, avoids scope creep, and creates ownership from day one.
✅ Outputs of Step 1 #
By the end of this step, you should have:
- ✅ Scope & boundary document
- ✅ Interface list or matrix
- ✅ Assumption log
- ✅ Input documents collected
- ✅ Team roster and meeting plan
- ✅ Timeline aligned with development milestones
- ✅ DFMEA planning sheet filled
📎 Internal Links #
- Download DFMEA Planning Template (Excel)
- Step 2: Structure Analysis – EWP Component Breakdown
- What Is an Interface Matrix in DFMEA?
🧩 Next Step #
Ready to proceed? Head to Lesson 4.2: Step 2 – Structure Analysis, where we build the design structure tree and function block diagram of the EWP.
