FMEA (Failure Mode and Effects Analysis): Step-by-Step Guide with Examples

🌟 Introduction: Why Every Engineer Should Master FMEA

In modern manufacturing and product development, preventing problems is far more valuable than fixing them.
That’s exactly what FMEA — Failure Mode and Effects Analysis — helps achieve.

FMEA is one of the most powerful tools in Quality and Reliability Engineering, enabling organizations to proactively identify potential failure points, assess their risk, and implement corrective actions before they lead to defects, downtime, or customer complaints.

From automotive and aerospace to healthcare and software, FMEA is an essential requirement under IATF 16949, ISO 9001, and APQP frameworks.

In this article, we’ll explore FMEA in depth — what it is, its purpose, step-by-step execution, real-world examples, and best practices to ensure your team applies it effectively.

⚙️ What is FMEA?

Failure Mode and Effects Analysis (FMEA) is a structured, systematic approach used to identify, analyze, and prioritize potential failures in a process, product, or system — and take preventive action before they occur.

📘 Formal Definition (AIAG-VDA Handbook 2019):

“FMEA is a structured approach to identifying and evaluating the potential failures of a design or process, the causes and effects of those failures, and the actions to mitigate the risk.”

In simpler words:

FMEA asks: What could go wrong? Why would it happen? What could be the consequence? And how can we prevent it?

🎯 Objectives of FMEA

• Identify potential failure modes in a design or process.

• Evaluate their effects and causes on quality, safety, and performance.

• Prioritize risks using Risk Priority Number (RPN) or Action Priority (AP).

• Recommend and implement preventive or corrective actions.

• Establish a living document that evolves with process improvements.

🧩 Types of FMEA

FMEA is categorized based on its application area:

In manufacturing, DFMEA and PFMEA are most widely used.

🧭 When Should FMEA Be Conducted?

• During new product development (APQP Phase 2 & 3).
• Before process launch or line approval.
• After design or process change (ECR/ECN).
• After customer complaints or field failures.
• When new technology, materials, or suppliers are introduced.

FMEA should be preventive, not reactive — it’s most effective when done early in the design or process development stage.

🪜 Step-by-Step Procedure for FMEA

Let’s explore FMEA using a 10-step approach aligned with AIAG-VDA 2019 methodology, which is now the industry standard.

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Step 1: Define Scope and Team

Begin by defining:

• The system, design, or process to be analyzed.
• The boundaries (start and end points).
• The multidisciplinary team — typically includes design, process, quality, and maintenance experts.

Example: For a PFMEA on a welding process, include the process engineer, quality engineer, maintenance person, and production supervisor.

Step 2: Structure Analysis

Break down the process or product into smaller components or steps:

• For DFMEA: structure by subassemblies, components, and functions.
• For PFMEA: use process flow diagrams to map each step.

This helps visualize where failures can occur.

Example: Machining → Cleaning → Inspection → Packing.

Step 3: Function Analysis

Define what each item, step, or component is supposed to do — its intended function and requirements.

Example: Function – “To weld two parts firmly.”
Requirement – “Weld must have minimum strength of 200 N/mm².”

Step 4: Failure Mode Identification

Ask the question:

“How can this function fail?”

List all possible failure modes — ways the function might not meet its intended purpose.

Example:

• Incomplete weld

• Weak joint

• Weld spatter

• Misalignment

Step 5: Effect Analysis

For each failure mode, identify the effect — what happens if this failure reaches the next process or customer.

Example:

• Incomplete weld → part separation in service

• Misalignment → improper fit during assembly

Each effect is rated using a Severity (S) score (typically 1 to 10).
High severity means a high impact on safety or customer satisfaction.

Step 6: Cause Analysis

Determine possible root causes of each failure mode — such as:

• Incorrect setup
• Machine wear
• Operator error
• Material defect
• Inadequate parameter control

Each cause is assigned an Occurrence (O) score — representing the likelihood of the failure happening.

Step 7: Control Analysis

Document existing process controls — what’s currently in place to prevent or detect the failure.

Example:

• Poka-Yoke device, torque check, inspection, or SPC chart.

Assign a Detection (D) score — indicating how likely the current control can detect the failure before it escapes.

Step 8: Risk Evaluation (RPN or Action Priority)

Traditionally, risk is quantified as:

RPN = Severity × Occurrence × Detection

Under the AIAG-VDA FMEA standard, however, Action Priority (AP) replaces RPN to prioritize based on S, O, and D combinations.

Step 9: Recommended Actions

For high-risk items, identify corrective or preventive actions such as:

• Process redesign
• Parameter optimization
• Training operators
• Adding detection systems (e.g., sensors, alarms)
• Updating Control Plan or Work Instructions

Assign responsibility and target date for each action.

Step 10: Follow-up and Reassessment

After implementing actions:

• Re-evaluate S, O, and D ratings.
• Document the new RPN/AP.
• Update the FMEA record.

FMEA is a living document — it must be continuously updated with lessons learned and improvements.

🧮 Example: Process FMEA for Drilling Operation

| Process Step | Potential Failure Mode | Effect of Failure | Severity (S) | Cause | Occurrence (O) | Control Method | Detection (D) | RPN |
|——————|—————————-|————————|——————|————|——————–|——————–|——————|
| Drilling hole | Hole oversize | Improper fit in assembly | 8 | Tool wear | 5 | Visual inspection | 6 | 240 |
| Drilling hole | Hole off-center | Misalignment | 7 | Fixture looseness | 4 | Go/No-Go gauge | 4 | 112 |

Action: Replace drill bit after fixed cycle time and add torque check for fixture.
After implementation, RPN reduces to 72 — showing effective risk mitigation.

🧰 Tools and Software for FMEA

Modern teams use software for efficiency and traceability:

• APIS IQ-FMEA
• PTC Windchill Quality Solutions
• ReliaSoft XFMEA
• ETQ Reliance
• Microsoft Excel (for manual templates)

These tools help link FMEA with Control Plans, PPAP, and CAPA systems.

📊 FMEA Ratings and Scales

Severity (S)

• 10 – Hazardous with no warning
• 9 – Hazardous with warning
• 7–8 – Major loss of function
• 5–6 – Moderate impact
• 3–4 – Minor effect
• 1–2 – No effect

Occurrence (O)

• 10 – Failure almost inevitable
• 7–9 – Repeated failures
• 4–6 – Occasional failures
• 2–3 – Rare
• 1 – Remote

Detection (D)

• 10 – No detection method
• 7–9 – Detection likely after shipment
• 4–6 – Detection through inspection possible
• 1–3 – Detection certain (Poka-Yoke, automation)

🧱 FMEA Linkage with APQP and Control Plan

FMEA is a critical document in APQP (Advanced Product Quality Planning), particularly in Phase 2 – Product Design & Development and Phase 3 – Process Design & Development.

Its results directly feed into:

• Control Plan (defining inspection & control methods)
• Work Instructions
• PPAP Submission Package

Thus, a strong FMEA ensures the process is capable, robust, and customer-ready.

🚀 Benefits of Implementing FMEA

• Reduces failure risk and warranty claims
• Improves product reliability and safety
• Saves cost of rework and recalls
• Increases process understanding and cross-functional collaboration
• Supports compliance with ISO/IATF standards
• Builds customer confidence and trust

❌ Common Mistakes in FMEA

1. Treating it as a paperwork exercise.
2. Conducting FMEA without a multidisciplinary team.
3. Using outdated templates or ignoring AIAG-VDA format.
4. Copy-pasting from previous FMEAs without real analysis.
5. Failing to link actions to Control Plan updates.
6. Not revising FMEA after changes or customer complaints.

FMEA should be a thinking process, not just a document.

📘 FMEA vs Root Cause Analysis (RCA)

Both are complementary — FMEA prevents issues, RCA solves them.

🧩 Example: FMEA in Automotive Industry (IATF 16949)

In an automotive assembly plant, PFMEA is mandatory for:

All manufacturing processes

PPAP documentation

Control Plan linkage

Example:
A PFMEA identified high risk (RPN 216) for torque variation in wheel nut tightening.
Action taken: Installed digital torque wrench with data logging and alarm.
Result: Defect rate dropped by 95%, RPN reduced to 64.

🧾 Conclusion

FMEA is not just a form — it’s a mindset.
It teaches teams to think proactively, identify risks, and design robust systems that produce quality every time.

Whether you’re working on a new automotive line, a medical device, or an industrial process, mastering FMEA ensures prevention is built into your product DNA.

By regularly updating and reviewing FMEA, you don’t just meet customer requirements — you create a culture of continuous improvement and operational excellence.

“An hour spent on FMEA saves ten hours of firefighting later.”