Design FMEA

Design FMEA (Failure Mode and Effects Analysis) is one of the most important tools used in industry to identify potential design issues before implementation. As an integral part of the design process, this method helps minimize the risk associated with design defects and ensures a higher level of product safety and quality.

In this article, we take a detailed look at what Design FMEA is, how it works, and what benefits it offers in the context of machine design, production line construction, and production process automation. We also discuss how Design FMEA compares with other risk analysis methods, such as risk analysis according to EN ISO 12100 under the Machinery Directive and the harmonized standard EN ISO 12100.

What is Design FMEA?

Design FMEA, or Design Failure Mode and Effects Analysis, is a systematic process used to identify potential defects in a design, assess the associated risk, and develop corrective actions to eliminate or minimize those defects.

FMEA dates back to the 1960s, when it was first developed by NASA to improve the safety of space missions. Over time, it came to be used in many other industries, including automotive, aerospace, medical, and many others.

The key difference between Design FMEA and other risk analysis methods, such as risk analysis under the Machinery Directive or the harmonized standard EN ISO 12100 (Risk analysis, assessment and evaluation), is its focus on potential design defects and their consequences for product functionality, rather than solely on safety-related risks.

Design FMEA methodology

The DFMEA process consists of several key steps that ensure a comprehensive analysis of potential design issues.

Identification of potential defects

The first step is to identify potential defects that may occur in the design. At this stage, the design team reviews each part of the design and considers what defects may arise and what consequences they may have.

Risk assessment

Next, a risk assessment is carried out for each identified defect using three key indicators:

• SEV (Severity) – the rating of the seriousness of the defect’s consequences,
• OCC (Occurrence) – the rating of the likelihood of the defect occurring,
• DET (Detection) – the rating of the likelihood of detecting the defect before it occurs.

Based on these indicators, the RPN (Risk Priority Number) is calculated, making it possible to prioritize defects and focus on those that present the greatest risk. In projects where design review also includes machinery safety, this can complement risk assessment according to ISO 12100.

1. Potential Failure Mode: Possible failure modes in the system or product.
   • Overheating: Overheating.
   • Mechanical Wear: Mechanical wear.
   • Software Bug: Software bug.
2. Potential Effect(s) of Failure: Potential effects of failure.
   • Overheating: May lead to component damage.
   • Mechanical Wear: May cause increased friction.
   • Software Bug: May lead to a system crash.
3. Severity (SEV): The seriousness of the effects of failure on a scale from 1 to 10.
   • Overheating: 8 (high severity).
   • Mechanical Wear: 7 (moderate severity).
   • Software Bug: 9 (very high severity).
4. Occurrence (OCC): The frequency of failure occurrence on a scale from 1 to 10.
   • Overheating: 5 (medium frequency).
   • Mechanical Wear: 6 (high frequency).
   • Software Bug: 4 (low frequency).
5. Detection (DET): The ability to detect the failure before it occurs on a scale from 1 to 10.
   • Overheating: 3 (medium detectability).
   • Mechanical Wear: 4 (low detectability).
   • Software Bug: 2 (high detectability).
6. Risk Priority Number (RPN): The risk priority number calculated as the product of SEV, OCC, and DET.
   • Overheating: 120.
   • Mechanical Wear: 168.
   • Software Bug: 72.

This table shows how DFMEA makes it possible to assess and prioritize risks associated with potential design defects, enabling corrective action to be taken to minimize those risks.

How often should a DFMEA analysis be carried out?

DFMEA should be carried out regularly and at key points throughout the product life cycle. Here are some guidelines on how often to perform a DFMEA:

1. At the start of the project: The first DFMEA should be performed during the concept or design stage, before the design is approved for production. This makes it possible to detect and eliminate potential issues early.
2. Whenever a significant design change is made: Any major design change, such as a modification to the design, a change of materials, or the introduction of new technologies or procedures, should trigger a new DFMEA. Such changes can introduce new risks that need to be assessed.
3. After problems are identified during the prototype phase: If issues or failures are found during the product’s prototype or testing phase, the DFMEA should be repeated to identify the source of the problems and implement appropriate corrections.
4. Regular periodic reviews: Even if no major design changes have been made, it is good practice to review the DFMEA at regular intervals (e.g. every 6-12 months). Regular reviews help confirm that earlier conclusions are still valid and that all potential risks are being properly managed.
5. After quality incidents or failures: If quality incidents or failures occur during production or product use, a DFMEA should be carried out to identify the causes of the problems and introduce preventive measures.
6. Before the product is launched: Before the product is commercially launched, it is worth conducting a final DFMEA to ensure that all potential risks have been identified and properly managed.

Regular DFMEA helps maintain high product quality, minimize risk, and continuously improve design and production processes.

Developing and implementing corrective action plans

The final step is to develop and implement corrective action plans aimed at eliminating or minimizing the identified defects. At this stage, the design team develops specific solutions and incorporates them into the design to reduce the risk of defects and their consequences.

Comparison of Design FMEA and PFMEA

In industry, both Design FMEA (DFMEA) and Process FMEA (PFMEA) are commonly used to assess and minimize risk. Although both methods are intended to identify and eliminate potential problems, they differ in scope and application.

Definition of PFMEA

PFMEA (Process Failure Mode and Effects Analysis) is an analysis of the causes and effects of process defects. This method focuses on identifying potential defects in manufacturing processes, assessing the associated risk, and developing corrective actions to eliminate or minimize those defects.

Key differences and similarities between Design FMEA and PFMEA

1. Scope of analysis:
   • Design FMEA: Focuses on identifying potential product design defects at the design stage, before the product goes into production. The analysis covers the product’s technical and functional aspects.
   • PFMEA: Focuses on identifying potential defects in the manufacturing process. The analysis covers operational and process-related aspects that may affect production quality and efficiency.
2. Stage of implementation:
   • Design FMEA: Used mainly during the product design stage, before the product is introduced into production.
   • PFMEA: Used during production to ensure that manufacturing processes are optimized and free from defects.
3. Purpose of the analysis:
   • Design FMEA: The goal is to ensure that the product design is free from defects that could affect its functionality and reliability.
   • PFMEA: The goal is to ensure that manufacturing processes are optimized and free from defects that could affect product quality.

Use of PFMEA in industry

PFMEA is widely used across many industrial sectors, including the automotive industry, aerospace, the pharmaceutical industry, and many others. It is particularly useful for identifying and eliminating process defects that can affect production quality and efficiency. PFMEA makes it possible to optimize manufacturing processes, which leads to higher product quality and lower production costs.

Examples of Design FMEA applications

Machine design

In machine design, DFMEA is an invaluable tool for identifying potential issues at the concept stage. This helps avoid costly changes later in the project and ensures the machine performs as intended. A design office should use this tool very frequently.

Production line construction

In the context of production line construction, Design FMEA helps identify and eliminate potential defects that may affect the efficiency and safety of the production line. This analysis makes it possible to optimize processes and ensure the line operates without disruption, especially in projects involving machine design and construction.

Industrial automation

In industrial automation, Design FMEA helps identify potential issues related to the integration of automation systems. This makes it possible to avoid situations in which the failure of one system component causes the entire production line to stop.

Production automation

In production automation, Design FMEA helps identify and eliminate potential issues related to the implementation of automated production systems. This ensures that these systems operate as intended and achieve the planned production targets.

Comparison with other risk analysis methods

DFMEA differs from other risk analysis methods, such as risk analysis according to EN ISO 12100 under the Machinery Directive and the harmonized standard 12100, which focus mainly on safety-related risks.

Risk analysis under the Machinery Directive

The Machinery Directive requires a risk analysis to ensure that the machine meets all safety requirements. It focuses on identifying and eliminating hazards that may pose a risk to machine operators and users, and in practice may also support CE certification of machinery.

Harmonized standard EN ISO 12100

The harmonized standard EN ISO 12100 also focuses on risk analysis related to machinery safety. It covers hazard identification, risk assessment, and the implementation of measures to eliminate or minimize risk.

Unlike these methods, DFMEA focuses on identifying potential design defects and their consequences for product functionality, which helps ensure higher product quality and reliability.

Benefits of using Design FMEA

Improved product quality

Design FMEA makes it possible to identify and eliminate potential design defects at an early stage of the project, resulting in higher final product quality.

Reduced costs related to repairs and errors

By identifying and eliminating design defects early in the project, Design FMEA can significantly reduce the costs associated with repairs and errors at later stages of production.

Increased production process efficiency

Design FMEA helps identify and eliminate defects that may affect the efficiency of production processes, resulting in higher productivity and lower production costs.

Challenges and best practices

Typical challenges in implementing Design FMEA

One of the main challenges in implementing Design FMEA is the need to involve the entire design team in the analysis process. This requires time and resources, but it is essential for effective defect identification and elimination.

Recommendations and best practices

To implement Design FMEA effectively, it is worth:

• Involving the entire design team in the analysis process,
• Regularly updating and reviewing the FMEA analysis,
• Using tools that support the analysis process, such as FMEA software.

Why should an industrial automation integrator prepare Design FMEA?

An industrial automation integrator should prepare Design FMEA because this analysis enables early detection of potential design defects and risks related to the integration of automation systems. This helps avoid costly changes at later project stages and ensures that the automation systems operate as intended.

This analysis also has a direct impact on PLC programming (Programmable Logic Controller). Design FMEA makes it possible to identify programming-related risks, such as logic errors, potential component failures, or suboptimal operating sequences. This supports better preparation of control code that is more fault-tolerant and helps maintain system continuity, which is also relevant in the context of a safe software house for industry.

In addition, preparing a Design FMEA makes it easier to develop designs aligned with TPM (Total Productive Maintenance), taking into account solutions such as Poka-Yoke (error-proofing mechanisms) or SMED (Single-Minute Exchange of Die – quick tool change). Integrating these methods into industrial automation projects contributes to higher efficiency (OEE), reduced downtime, and improved product quality; for example, design assumptions may also support SMED in machine design for high OEE.

Pharmaceuticals: GMP vs FMEA

In the pharmaceutical industry, compliance with GMP (Good Manufacturing Practice) principles is essential to ensure the quality and safety of medicinal products. Design FMEA plays an important role here because it helps identify and eliminate potential design flaws at the equipment and production system design stage, in line with GMP requirements.

GMP places strong emphasis on hygienic design solutions, such as ease of cleaning and disinfection, minimizing the risk of cross-contamination, and ensuring full compliance with pharmaceutical manufacturing regulations. Design FMEA helps identify and assess hygiene-related risks and implement appropriate corrective measures, supporting compliance with stringent GMP requirements.

Other analyses in the context of machine and production line design

In addition to Design FMEA, other analyses are also used in the process of designing machines and production lines, such as Design for Assembly (DFA). DFA focuses on designing products in a way that simplifies assembly, leading to lower production costs, shorter assembly times, and fewer errors.

DFA helps identify design features that may be difficult to assemble or that may lead to assembly errors. This makes it possible to introduce design changes that simplify assembly and improve the quality of the final product. In some cases, design verification can also be supported by strength calculations (finite element analysis).

Combined with Design FMEA, DFA enables the development of more efficient and reliable production systems. Integrating these methods supports a comprehensive approach to machine and production line design, covering quality and safety as well as production efficiency.

Design FMEA is an invaluable tool in the process of machine design, production line construction, and production process automation. It makes it possible to identify and eliminate potential design flaws at an early project stage, resulting in higher product quality, reliability, and efficiency. Compared with other risk analysis methods, Design FMEA stands out because it focuses on design defects rather than only on risks related to machine safety. Implementing Design FMEA involves certain challenges, but the benefits it delivers clearly outweigh those difficulties. In modernization projects, it can also complement activities related to adapting machines to minimum requirements.