Practical Application of AIAG-VDA FMEA
FMEA (Failure Mode and Effects Analysis) is a core tool in quality management. The new AIAG-VDA FMEA (2019 edition) has undergone significant upgrades in structure, scoring rules, and application logic compared to the old version (4th edition). This article systematically explains the key changes in the new FMEA, practical steps, scoring standards, and provides a standardized Excel template suitable for quality control scenarios in the automotive, electronics, and machinery industries.
? Core Value: Master the implementation methods of the new FMEA, transitioning from "post-incident rectification" to "pre-incident prevention," reducing the risk of product/process failure, aligning with IATF16949 system requirements, and enhancing the company's quality control level.
? Click to download the new FMEA (AIAG-VDA) Excel practical template
1. Key Changes in the New FMEA (AIAG-VDA)
The new FMEA (AIAG-VDA) has made significant changes in five dimensions compared to the old version (4th edition), placing greater emphasis on "risk prevention" and "structured analysis":
| Comparison Dimension | Old FMEA (4th Edition) | New FMEA (AIAG-VDA) |
|---|---|---|
| Structural Framework | Linear analysis based on "failure mode - failure effect - failure cause" | Adopts a three-tier structure of "structure tree - function tree - failure tree," more systematic |
| Scoring Rules | Severity (S), Occurrence (O), Detection (D) scored 1-10, RPN = S × O × D | Severity (S), Occurrence (O), Detection (D) scored 1-10, introduces AP (Action Priority) to replace RPN as the decision-making basis |
| Analysis Logic | Focuses on post-failure analysis | Focuses on pre-failure prevention, emphasizing "function first" |
| Type Classification | DFMEA and PFMEA are separate, with no unified framework | Unified framework for DFMEA and PFMEA, introduces SFMEA and MFMEA |
| Action Requirements | Only when RPN exceeds the threshold action is required | Actions are classified by AP (high/medium/low), high priority must have improvement measures |
2. Core Terminology and Definitions of the New FMEA
- Structure Tree: Clearly defines the analysis object and scope
- Function Tree: Defines the "intended function" of the analysis object, which is the foundation of failure analysis
- Failure Tree: Analyzes the modes, effects, and causes of functional failures
- AP (Action Priority): The core decision-making indicator in the new version, replacing the old RPN
- DFMEA: Design FMEA, for the product design phase
- PFMEA: Process FMEA, for the production/assembly process
3. Practical Steps for the New FMEA (AIAG-VDA)
- Step 1: Define the Analysis Scope — Determine the analysis process and draw the structure tree
- Step 2: Define Functions and Requirements — Function descriptions must be "measurable and verifiable"
- Step 3: Analyze Failure Modes — Identify specific modes of functional failure
- Step 4: Evaluate Failure Effects — Score according to the severity (S) rating criteria
- Step 5: Identify Failure Causes — Score according to the occurrence (O) rating criteria
- Step 6: Evaluate Detection Capability — Score according to the detection (D) rating criteria
- Step 7: Determine Action Priority — Develop measures based on the AP decision rules
4. Scoring Standards for the New FMEA
4.1 Severity (S) Scoring Standards
| Score | Failure Effect | Example |
|---|---|---|
| 10 | Endangers personal safety/violates regulations | Brake failure causing an accident |
| 9-8 | Product completely fails, customer cannot use it | Motor fails to start |
| 7-6 | Product function severely degrades | Motor torque is insufficient |
| 5-4 | Product function slightly degrades | Motor noise exceeds standards |
| 3-2 | No impact on product function, only minor rework required | Label is misaligned |
| 1 | No impact whatsoever | No failure |
4.2 Occurrence (O) Scoring Standards
| Score | Frequency of Failure | Example |
|---|---|---|
| 10 | Almost always occurs (＞90%) | Processing with uncalibrated equipment |
| 9-8 | Frequently occurs (50%-90%) | Employees not following SOPs |
| 7-6 | Often occurs (10%-50%) | Unstable incoming material batches |
| 5-4 | Occasionally occurs (1%-10%) | Intermittent equipment failure |
| 3-2 | Rarely occurs (＜1%) | Employee misoperation |
| 1 | Almost impossible to occur | Multiple verification processes |
4.3 Detection (D) Scoring Standards
| Score | Detection Capability | Example |
|---|---|---|
| 10 | No detection measures at all | No inspection, no monitoring |
| 9-8 | Weak detection measures | Manual visual inspection |
| 7-6 | Average detection measures | First article inspection |
| 5-4 | Good detection measures | Process patrol inspection |
| 3-2 | Excellent detection measures | Automated online detection |
| 1 | Perfect detection measures | Poka-yoke tooling |
? AP (Action Priority) Decision Rules
High Priority: S≥9 and O≥5 and D≥5 → Immediate corrective actions must be taken
Medium Priority: S≥5 and O≥5 or D≥5 → Recommended to take corrective actions
Low Priority: S≤4 and O≤4 and D≤4 → No immediate action required, continuous monitoring
High Priority: S≥9 and O≥5 and D≥5 → Immediate corrective actions must be taken
Medium Priority: S≥5 and O≥5 or D≥5 → Recommended to take corrective actions
Low Priority: S≤4 and O≤4 and D≤4 → No immediate action required, continuous monitoring
5. Industry Practical Case (Automotive Parts PFMEA)
Case Background: A car brake caliper manufacturing company, the old FMEA did not identify the "caliper piston sticking" failure mode, leading to a customer complaint rate of 5‰. After re-analyzing with the new FMEA, the customer complaint rate dropped from 5‰ to 0.1‰.
? Download the new FMEA (AIAG-VDA) Excel practical template again
? Template Adaptation Explanation:
1. The template includes two worksheets for DFMEA and PFMEA, compatible with the new AIAG-VDA framework;
2. Built-in S/O/D scoring standards and AP decision formulas, automatically calculates priority;
3. Compatible with Excel 2016 and above, WPS.
2. Built-in S/O/D scoring standards and AP decision formulas, automatically calculates priority;
3. Compatible with Excel 2016 and above, WPS.