VDA Field Failure Analysis is a solution for: when a “broken” part turns out to be fine.Every driver knows this scenario: something rattles, something stops working, and after a visit to the workshop the mechanic says, “This part needs to be replaced.” The car gets fixed, the bill is paid, and yet a question lingers in your mind: was the replaced part really defective?
In most cases, its story doesn’t end there. On the contrary – it’s just beginning. The replaced component embarks on a journey to the manufacturer’s laboratory, where it undergoes a precise market returns analysis. Its purpose is simple: to understand why the product failed – or whether it failed at all.
This is the essence of the VDA Field Failure Analysis (FFA) – a standard that helps the automotive industry not only solve problems reported from the field but also learn from them and prevent their recurrence in the future.
What is VDA Field Failure Analysis?
VDA Field Failure Analysis (Market Returns Analysis) is a standard developed by the German Association of the Automotive Industry (VDA).
It defines uniform procedures for handling returned parts that customers have reported as defective.
In short, it is a systematic method for identifying, analyzing, and eliminating the root causes of failures that occur during actual product use by the end customer.
The goal of VDA FFA is to establish a common language across the entire supply chain – from OEMs to Tier 1 and Tier 2 suppliers, and even service workshops. Thanks to this unified approach, everyone knows exactly how to act when a field issue occurs.
VDA FFA is not just a technical tool; it’s an integral part of the quality management system that directly contributes to:
- faster response to field issues,
- reduced warranty costs,
- improved product reliability,
- and strengthened customer trust.
Why is market returns analysis so important?
It is quite common in the automotive industry that many claimed parts show no defects during laboratory tests. This phenomenon is known as NTF (No Trouble Found) – meaning no confirmed failure.
For automotive manufacturers, this represents a major challenge – and a significant cost.
Every such case means that resources (people, time, laboratories) were dedicated to investigating a part that… actually works.
That’s why it’s crucial to determine whether the problem truly lies in the part itself, or rather in:
- the interaction between components,
- diagnostic errors in the workshop,
- incorrect assembly,
- software or firmware issues,
- or even the way the vehicle was used.
The VDA Field Failure Analysis process was designed precisely for that – to systematically and cost-effectively identify the true root cause of a problem.
Another reason why VDA FFA is important is the requirements of OEMs, which require market returns analysis. However, OEMs also have additional requirements for market returns analysis:
- Mercedes: MBN 10448 “Field Failure Analysis”
- VW Group: IATF CSRs for section 10.2.5, which requires the implementation of NTF based on the VDA FFA manual
- BMW: GS 95004 “Failure analysis – Part analysis of field complaints” standard
The architecture of VDA Field Failure Analysis
VDA FFA follows an escalation model, meaning the process begins with simpler, standard tests and gradually advances to more complex and detailed investigations as needed.
The process can be divided into three main phases:
- Part Analysis
- NTF Process (No Trouble Found)
- Problem-Solving Process
Each of these stages serves a different purpose and involves different functions across the organization.
1. Part Analysis – the first look at the problem
This is the technical “autopsy” of the component. The goal is to determine whether the returned part is actually defective and whether the issue reported by the customer can be reproduced under controlled test conditions.
Step 1: Standard Test
This is the basic inspection performed at ambient temperature to detect permanent, repeatable faults. For electronic parts, the error memory is read to identify any clues about what might have triggered the failure.
Step 2: Test Under Load
If the standard test does not confirm the failure, the component undergoes a second, more demanding stage. The part is exposed to extreme conditions – temperature changes, humidity, vibration, and voltage fluctuations – to recreate the environment in which the fault occurred in the vehicle. This is where engineers often uncover intermittent or hidden defects that only appear under certain conditions.
Test results classification
After testing, the part is classified as:
- NOK – fault confirmed and matches the customer complaint,
- OK based on analysis – no defect found,
- NTF – failure cannot be reproduced.
It’s this NTF result that triggers the next phase of the process.
2. The NTF Process – investigating the “ghosts” of quality
When the part seems to work perfectly but the customer keeps reporting a problem, a deeper investigation begins.
The NTF (No Trouble Found) process is not about saying “nothing’s wrong,” but about looking for causes beyond the part itself. Note that NTF analysis is required by IATF 16949.
The three pillars of NTF:
- Data Collection and Evaluation
This includes analyzing repair history, vehicle data, fault codes, production records, and information from other markets.
The aim is to identify correlations and recurring patterns. - System Tests
The part is tested as part of a larger system – in a simulated environment or even in the actual vehicle.
Often, only at this level do the real interaction problems between components become visible. - Process Assessment
This step examines whether the root cause lies outside the technical system – for example, in service diagnostics, documentation, or software programming procedures.
The NTF process therefore represents a shift in perspective – from analyzing a single part to investigating the entire system. It requires close cooperation between quality, R&D, production, and service engineering teams.
3. Problem-Solving Process – from cause to action
Once the cause of the failure has been identified, the final phase begins – the Problem-Solving Process, designed to permanently eliminate the issue.
Step 1: Root Cause Analysis
Structured methods such as 5 Why, Ishikawa Diagram, or Fault Tree Analysis (FTA) are used to determine why the failure occurred, not just what failed.
Step 2: Corrective Actions
Based on the root cause, permanent corrective measures are implemented. These may affect product design, manufacturing processes, or service procedures.
Step 3: Effectiveness Verification
Implementing a fix is not enough – its effectiveness must be verified. Manufacturers monitor field data over time to ensure the issue no longer recurs.
Planning the market returns analysis
The VDA standard emphasizes that an effective market returns analysis must be planned already during product development, regardless if it is according to APQP or VDA MLA.
Before the vehicle reaches the market, engineering teams must prepare:
- detailed test specifications,
- triggering criteria for the NTF process,
- resource and competency plans,
- and a strategy for sampling and returning parts from the field.
Only then can the organization react quickly and efficiently when the first field returns appear.
Measuring VDA FFA effectiveness – key performance indicators (KPIs)
VDA defines a set of KPIs that help monitor and improve the effectiveness of the entire FFA process.
Among the most important are:
- Average part analysis time – from receipt of the part to the completion of analysis.
- Share of OK parts – percentage of returned components found to be functional.
- Share of confirmed failures in standard or load testing.
- Return logistics time – the time it takes for parts to be shipped to and from the supplier.
- Correlation between analyzed parts and field data.
Tracking these metrics enables both OEMs and suppliers to pinpoint weak points and drive continuous improvement.
Auditing the VDA Field Failure Analysis process
An integral part of the standard is the FFA audit, structured in accordance with VDA 6.3 methodology. Requirements for the analysis of defective parts from the market are already included in individual sections of the commonly used catalog of questions and measurement criteria. For example, VDA 6.3 – P3.4; P4.7; P7.4. Existing process audits focus on the product development and production processes. However, it is important to remember that the audit for the analysis of defective parts from the market is a standalone audit standard. It addresses the specific requirements of the analysis process for defective parts from the market.
The audit covers seven key areas, including:
- organization and planning of the analysis,
- execution of data analysis,
- the NTF process,
- part analysis,
- and the problem-solving process.
The audit result defines the organization’s capability level in market returns analysis:
- A – capable,
- B – conditionally capable,
- C – not capable (triggering escalation actions).
Field Failure Analysis as a driver of continuous improvement
VDA FFA is not a reactive process – it’s a key part of quality culture. Every confirmed issue becomes a lesson learned, and every NTF case becomes an opportunity to expand understanding of how products behave in real-world conditions.
In practice, this means that an organization:
- closes the quality feedback loop,
- uses market data to improve products,
- and strengthens customer trust through transparency and responsiveness.
As a result, market returns analysis becomes fuel for innovation and reliability, not merely a mandatory procedure imposed by OEM requirements.
Conclusions: When a return becomes a source of knowledge
What may appear to the customer as a simple failure is, for quality engineers, a valuable source of technical insight. Each returned part tells a story – about design, production, usage, and the potential for improvement.
VDA Field Failure Analysis helps decode that story.
With its structured methodology, defined stages, and measurable performance indicators, companies can turn customer problems into engineering knowledge – and that knowledge into lasting product excellence.
If you would like to learn more about warranty management from the AIAG perspective, please read the article “Warranty Management – The Idea, Process and QMS Requirements”.
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For people who want to know more:
VDA QMC, Field Failure Analysis & Audit Standard, 2nd revised edition, November 2018
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