Failure Mode and Effects Analysis (FMEA) in Product Development
- 77 Teknik
- Sep 8
- 7 min read
Risk Prev ention for Reliable Manufacturing
In today’s competitive industrial environment, product reliability and quality are critical for customer satisfaction and long term success. Industries such as automotive, aerospace, medical, and defense cannot afford failures, as even minor defects can lead to safety issues, recalls, or financial losses.
This is why Failure Mode and Effects Analysis (FMEA) is one of the most important preventive quality tools. It ensures risks are detected and eliminated before they cause production problems or end-user failures.
What Is FMEA?
Failure Mode and Effects Analysis (FMEA) is a proactive, systematic approach used to identify potential failure modes in a product, system, or process, assess their impact, and prioritize actions to mitigate risks before issues arise. It’s widely used in industries like automotive, aerospace, medical devices, and manufacturing to enhance reliability, safety, and quality by addressing problems early in the design or operational phases. Below, I’ll expand on the concept, types, and applications of FMEA, including detailed explanations of Design FMEA (DFMEA) and Process FMEA (PFMEA), as well as the methodology, benefits, and key considerations.
FMEA is a structured risk management tool that helps teams anticipate what could go wrong, evaluate the severity of potential failures, and implement preventive measures. It involves analyzing components, systems, or process steps to:
Identify failure modes: Ways in which a product, component, or process could fail to perform its intended function.
Assess effects: The consequences of each failure mode on the system, process, or end-user.
Determine causes: Root causes or factors that could lead to the failure.
Prioritize risks: Using metrics like severity, occurrence, and detection to calculate a Risk Priority Number (RPN).
Mitigate risks: Recommend and implement actions to reduce the likelihood or impact of failures.
FMEA is typically conducted by cross-functional teams, including engineers, designers, quality assurance professionals, and process operators, to ensure a comprehensive analysis. The goal is to shift from reactive problem-solving (fixing issues after they occur) to predictive and preventive strategies (addressing risks before they manifest).
Key Components of FMEA
FMEA uses a structured approach with the following key elements:
Failure Mode: The specific way a component, system, or process could fail (e.g., a bolt breaking, a weld cracking, or a software glitch).
Effect: The impact of the failure on the system, process, or customer (e.g., reduced performance, safety hazards, or production delays).
Cause: The underlying reason for the failure (e.g., material fatigue, improper machining, or human error).
Severity (S): A ranking (typically 1–10) of how serious the effect is, with 10 being catastrophic (e.g., loss of life or complete system failure).
Occurrence (O): A ranking (1–10) of how likely the failure is to occur, with 10 being very likely.
Detection (D): A ranking (1–10) of how likely the failure is to be detected before reaching the end-user, with 10 indicating low detectability.
Risk Priority Number (RPN): Calculated as S × O × D, this score (1–1000) helps prioritize which failure modes need immediate action. Higher RPNs indicate higher risk.
Recommended Actions: Steps to reduce severity, occurrence, or improve detection (e.g., redesigning a component, adding quality checks, or improving training).
Types of FMEA
FMEA can be applied at different stages of product development or operations, with two primary types: Design FMEA (DFMEA) and Process FMEA (PFMEA). Other specialized types exist (e.g., System FMEA, Software FMEA), but DFMEA and PFMEA are the most common.
1. Design FMEA (DFMEA)
Focus: Identifies potential risks in the design phase of a product or system before it is manufactured.
Scope: Analyzes design elements such as geometry, materials, tolerances, interfaces, and functional requirements.
Objective: Ensure the product is robust, safe, and meets customer requirements by addressing design flaws early.
Examples of Failure Modes:
A car door latch failing to secure due to poor material selection.
A circuit board overheating due to inadequate heat dissipation in the design.
A medical device delivering incorrect dosages due to a software logic error.
Key Questions:
Does the design meet performance and safety requirements under all conditions?
Are materials and tolerances suitable for the intended use?
Could interfaces between components fail (e.g., poor fit or connectivity)?
Example Application:
In automotive design, DFMEA might evaluate a suspension system to ensure components like springs or shocks won’t fail under heavy loads or extreme temperatures. The team might identify a failure mode like “spring fatigue” caused by low-quality steel, with effects like reduced vehicle control (severity: 8). If the occurrence is moderate (5) and detection is difficult (7), the RPN would be 8 × 5 × 7 = 280, prompting a redesign with stronger materials.
2. Process FMEA (PFMEA)
Focus: Identifies risks in the manufacturing or operational processes used to produce a product or deliver a service.
Scope: Examines process steps like machining, welding, assembly, inspection, or packaging to uncover inefficiencies, errors, or defects.
Objective: Optimize processes to ensure consistent quality, reduce waste, and prevent defects from reaching customers.
Examples of Failure Modes:
Incorrect torque applied during assembly, causing loose bolts.
Weld imperfections due to improper equipment settings.
Contamination of a pharmaceutical product during packaging.
Key Questions:
Are process parameters (e.g., temperature, pressure) correctly set to avoid defects?
Could human error or equipment failure lead to process deviations?
Are quality control measures sufficient to catch defects?
Example Application:
In a CNC machining process for aerospace parts, PFMEA might identify a failure mode like “incorrect hole diameter” caused by tool wear. The effect could be a part rejection (severity: 6), with high occurrence due to infrequent tool checks (occurrence: 7) and moderate detection through manual inspection (detection: 5). The RPN (6 × 7 × 5 = 210) might lead to implementing automated tool wear monitoring.
FMEA Methodology
The FMEA process follows a structured sequence, typically documented in a standardized worksheet. Here’s a step-by-step overview:
Define Scope: Determine whether the FMEA is for a product design (DFMEA) or a process (PFMEA) and identify the system, subsystem, or process steps to analyze.
Assemble Team: Include experts from design, engineering, manufacturing, quality, and other relevant areas.
Identify Failure Modes: Brainstorm all possible ways each component or process step could fail.
Analyze Effects and Causes: For each failure mode, list its potential effects and root causes.
Assign Ratings:
Severity (S): Based on the worst-case impact (e.g., safety, performance, or cost).
Occurrence (O): Based on historical data, simulations, or engineering judgment.
Detection (D): Based on current controls (e.g., inspections, tests) to catch the failure.
Calculate RPN: Multiply S × O × D to prioritize risks.
Develop Actions: Propose design changes, process improvements, or additional controls to reduce RPN.
Implement and Monitor: Apply recommended actions and reassess RPN to verify effectiveness.
Document and Update: Maintain an FMEA document as a “living” record, updating it as new risks or data emerge.
Sample FMEA: CNC Milling Machine – Spindle System
Process Step / Function | Potential Failure Mode | Potential Effects of Failure | Severity (S) | Potential Causes | Occurrence (O) | Current Controls (Prevention / Detection) | Detection (D) | RPN (S × O × D) | Recommended Actions |
Spindle rotation | Bearing wear | Poor surface finish, vibration, part rejection | 8 | Lack of lubrication, overload, contamination | 5 | Scheduled maintenance, lubrication system | 5 | 200 | Use vibration monitoring sensors, improve lubrication schedule |
Tool clamping | Tool slips in spindle | Broken tool, scrap parts, machine damage | 9 | Insufficient clamping force, wear on clamping system | 3 | Torque checks, operator inspection | 4 | 108 | Introduce automatic tool clamp force monitoring |
Cooling system | Coolant pump failure | Tool overheating, reduced tool life, surface defects | 7 | Pump motor failure, clogging | 4 | Manual inspection, preventive replacement | 6 | 168 | Install coolant flow sensors with alarms |
Speed control | Incorrect spindle RPM | Wrong cutting speed, tool wear, quality issues | 8 | Sensor malfunction, software error | 2 | Operator input check, software limits | 5 | 80 | Add real-time spindle speed feedback loop |
Power supply | Voltage fluctuation | Spindle stops, production downtime | 10 | Grid instability, faulty power module | 2 | UPS backup, surge protectors | 3 | 60 | Add redundancy and predictive power monitoring |
Notes:
Severity (S): 1 = no effect, 10 = catastrophic (safety, compliance, or major downtime).
Occurrence (O): 1 = unlikely, 10 = very frequent.
Detection (D): 1 = easily detected, 10 = not detected until failure.
RPN (Risk Priority Number) = S × O × D → helps prioritize risks.
Actions focus on reducing severity (design change), occurrence (preventive maintenance), or detection (monitoring/inspection).
Benefits of FMEA
Early Risk Detection – Problems identified before mass production
Improved Product Reliability – Higher performance and durability
Lower Costs – Avoid late-stage redesigns and recalls
Enhanced Safety – Reduced chances of accidents or failures
Customer Confidence – Reliable products build trust and reputation
Compliance with Standards – Especially important in regulated industries
Challenges and Considerations
Subjectivity: Severity, occurrence, and detection ratings rely on team judgment, which can vary. Calibration with historical data or industry standards helps.
Time-Intensive: FMEA requires significant effort, especially for complex systems or processes. Prioritizing critical components can streamline the process.
Incomplete Analysis: Missing potential failure modes or causes can undermine effectiveness. Comprehensive brainstorming and data review are essential.
RPN Limitations: A high RPN doesn’t always mean the highest priority (e.g., a high-severity failure with low occurrence may need attention despite a lower RPN).
Continuous Updates: FMEA must be revisited as designs evolve, processes change, or new failure data emerges.
Applications Across Industries
Automotive: DFMEA ensures vehicle components (e.g., brakes, engines) meet safety and performance standards. PFMEA optimizes assembly lines to prevent defects.
Aerospace: DFMEA evaluates critical systems like avionics or landing gear. PFMEA ensures precision in manufacturing processes like composite bonding.
Medical Devices: DFMEA ensures devices like pacemakers or infusion pumps are safe and reliable. PFMEA prevents contamination or assembly errors.
Electronics: DFMEA addresses circuit board failures due to thermal stress. PFMEA ensures soldering or component placement is defect-free.
Software: While less common, FMEA can analyze software failure modes, like bugs or logic errors, impacting functionality or security.
77 Teknik’s Approach to FMEA
At 77 Teknik, we integrate FMEA into every stage of development and production:
Design Stage (DFMEA): Using CAD/CAM and simulations to predict risks early
Prototype Stage: Testing and validation to ensure design safety
Process Stage (PFMEA): Monitoring machining, welding, and assembly processes
Quality Stage: Advanced metrology and inspection methods to verify performance
Continuous Improvement: Updating risk analysis with real-world production data
This ensures our clients receive safe, reliable, and cost-effective products that meet the highest industry standards.
Minimize Risks, Maximize Reliability with FMEA
Do you want to develop products that are safer, more reliable, and cost-efficient?
