DFMEA | Design FMEA
Definition
The design FMEA (D-FMEA) is a subarea of the FMEA and is often also referred to as the Construction FMEA. This analysis is intended to identify weaknesses in the constructive design of a product at an early stage and to contribute to increasing system safety, reliability and availability through optimizing measures. I.e., it identifies potential risks that may arise during development or as a result of changes in the design of a product.
The D-FMEA not only considers the individual parts of a product, but also what requirements the end product has for the individual parts. On the basis of the D-FMEA, failure avoidance in the development process is optimized. Through an objective evaluation of the design requirements and alternatives, possible design errors are identified with greater probability.
DFMEA according to the AIAG/VDA Handbook
The current guideline from the industry associations AIAG and VDA has developed 7 steps for performing an FMEA (respectively DFMEA, PFMEA and FMEA MSR). It thus enables European and North American suppliers to produce accurate, complete and robust FMEAs that meet all customer requirements.
This means that FMEAs are no longer considered separately from the product development process, but are now an integral part of the development process.
The 7 steps of the DFMEA
Step 1: Planning and preparation
Step 1 "Planning and Preparation" is an integral part of D-FMEA, as it lays the foundation for further analysis. It helps to achieve more transparency in the analysis and a more efficient process through the clear delineation of the scope to be considered, as well as the common understanding of the team members about timing, scope and depth of analysis.
- Project plan and project description
- Identification of relevant existing findings (lessons learned)
- Definition and selection of the scope of analysis
Step 2: Structure analysis
The second step analyzes the structure of the respective FMEA (System FMEA, Construction/ Design FMEA).
- Identification of the relevant system elements
- Definition of the system structure
- Visualization of the scope of the analysis
- Analysis of relationships, interfaces, interactions
Step 3: Functional analysis
In the third step of the FMEA, the functions described by requirements and specifications are assigned to the system element.
The functional analysis describes the technical dependencies between functions at the different levels.
- Overview of the functionality of the product or process
- Assignment of requirements/characteristics to individual functions
- Visualization (function network/tree)
Step 4: Failure analysis
From the functions defined in step 3, the failure functions (failures) are derived in the fourth step.
During the failure analysis, causes and effects as well as their interrelationships are identified.
- Identification of the potential failures related to the function of a system element
- Creation of the error chains
- Visualization of the fault relationship (networks)
Step 5: Risk analysis
Step 5 deals with the topic of risk analysis. Its purpose is to identify risks by evaluating significance, occurrence and detection for each fault chain.
- Assignment and evaluation of prevention measures
- Assignment evaluation of detection measures
Step 6: Optimization
The main purpose of optimization in Step 6 of the FMEA is to determine actions to reduce risk and increase safety, thereby increasing customer satisfaction. This is done by:
- Identification of improvement measures
- Assignment of responsibilities and deadlines
- Implementation and documentation of the measures
- Reassessment of the risk
Step 7: Documentation of results
In order to follow the continuous improvement approach, the results are documented in step 7 - both for internal and external reporting.
Step 7 is not necessarily the last step. Results documentation can also be used earlier for defined milestones, for status reports on the current state of development, and for presenting defined but not yet implemented optimizations.
- Summary in a report
- Scope of the FMEA
- Description of the derivation of the functions
- B/A/E evaluation tables
- Description of the derived further procedure
