Aiag Fmea Latest Edition Pdf
Elia Khensamphanh
During the first six months after the publication of its first edition in June 2019, the AIAG & VDA FMEA Handbook gained popularity in the global automotive industry. Both U.S. and European OEMs have started to require the AIAG VDA approach to failure mode and effects analysis (FMEA) in their programs. Like the AIAG Guidebook, fourth edition, the handbook provides guidance, instruction, and illustrative examples of the requisite analytical techniques. The activities and analyses historically involved in FMEA have been formalized as discrete steps in the handbook.
The seven-step approach described in the handbook and outlined here guides the development of design, process, and supplemental monitoring and system response of FMEA through the sequencing (and the iteration) of described activities.
Some dedicated FMEA software systems, notably the Omnex AqUA Pro software, acknowledge the important need to include the analysis of integration and interface failures at the focus-element level. DFMEA improvement should be focused on causes of failure that are within the control of the FMEA team, vs. just assigning causes to the supplier or to a lower-level product.
Additionally, the handbook illustrates the relationship among different levels of product: system, subsystem, components, and feature characteristics, failure effects, failure modes, and failure causes cascade from one product level to the next. (See figure 2 below.)
Effect of failure on the end-user, the plant personnel, and the production operation at the next-higher level are separately identified. Note: The effect of failure on the end-user is communicated from the design to the process FMEA. The PFMEA relies on this information to comprehensively address effect.
Omnex continues to incorporate innovations to FMEA. Most recently it has developed a methodology for identifying and including multipoint failures in the design FMEA. Using this approach, the DFMEA would serve as a repository for potential faults and failures resulting from the simultaneous and sequential causes, in addition to the traditional single causes. Additionally, the multipoint FMEA allows the FMEA, failure mode effects and diagnostic analysis (FMEDA), and fault-tree analysis to link; this is especially important to mechatronic and electronic designs.
On Nov. 27, 2017, the Automotive Industry Action Group (AIAG) made a draft available of the AIAG-VDA FMEA Handbook that they co-developed with members from the VDA for a 90-day stakeholder review and commenting period. In response to that request I wrote the article "The Case Against the AIAG VDA DFMEA" which was published by Quality Digest on January 31, 2018 -management-column/case-against-aiag-vda-dfmea-013118.html . Within that article I explained that the FMEA process contained within the manual was not a harmonization of the 2008 AIAG 4th Edition FMEA Methods and the 2012 VDA FMEA Methods but rather an adoption of the fundamentally flawed German software driven VDA FMEA methodology that was first published in the form of a VDA FMEA manual in 1996.
"Organizations preparing DFMEAs should follow the AIAG Potential Failure Mode and Effects Analysis (FMEA). The AIAG/VDA Failure Mode and Effects Analysis (FMEA), Design FMEA and Process FMEA Handbook may be used, with analysis documented on the alternate form (Form B)."
Perhaps even more telling about the US automotive industry feelings about AIAG VDA FMEA methodology is the new revision of the SAE J1739 FMEA Manual Revision that has been delayed due to COVID-19. The SAE J1739 FMEA Manual is considered to be the FMEA bible for the US auto industry. It has aligned with the AIAG FMEA manuals for the last 18 years. I participated on a panel that included members of the SAE J1739 FMEA Manual Committee to discuss the pros and cons of the new AIAG VDA FMEA Handbook. Several members of the SAE J1739 FMEA Manual committee advised the audience to wait on the new version of the SAE J1739 FMEA Manual before moving to the AIAG VDA FMEA Handbook methodology. Based on their comments, the new SAE J1739 version is not going the adopt the AIAG VDA FMEA methodology. With its 120,000 members, the SAE has considerable power in the US automotive industry. Before purchasing any AIAG VDA FMEA Handbook related software or training, I would wait on the SAE FMEA Manual. You may not even have to change.
The DFMEA, when properly performed, is a risk assessment of the adequacy of the design (current hardware specifications) in defining a product that will meet the design requirements. Let us examine how the ISO 9001:2015 risk terms are translated to DFMEA terms.
4. The potential Hardware Specification mistakes that may be present in the design being assessed that could lead to the objectionable event (Failure Mode) are placed in the Failure Cause column of the DFMEA.
5. The Prevention and Detection Design Controls columns of the DFMEA are used to capture the risk controls that will be used to determine the probability of the (event) Failure Mode occurring due to the Failure Cause (potential improper hardware specification) listed.
6. The results of the Prevention and Detection Risk controls are used to establish the probability of the Failure Mode due to the Failure Cause. A number corresponding to this probability is placed in Occurrence rating column.
8. Any line in the DFMEA with a residual risk symbol (aka Special Characteristic symbol) must be worked on by the Design Engineer because the symbol indicates if the Design is manufactured as currently specified it will expose the user and/or company making the product to an objectionable level of risk.
The PFMEA, when properly performed, is a risk assessment of the adequacy of the process (suppliers, process equipment, process controls) in producing a product to the hardware design specifications. Any time an out of spec condition is created (PFMEA Failure Mode) there is an exposure to circumstances (PFMEA Failure Mode Effects and Severity Rating). Prevention and Detection risk controls are used to reduce the risk. When the PFMEA Class column is properly populated the Special Characteristic symbol for each row of the PFMEA it is determined using the Severity and Occurrence ratings from the row. The PFMEA special characteristic placed in the Class column represents the residual process risk that remains after the Prevention and Detection controls are implemented.
The Omnex methodology states that the special characteristics are to be transferred from the DFMEA to the PFMEA. This cannot be true since the DFMEA Class column entries when properly determined are representative of design residual risk and PFMEA Class column entries when properly determined are representative of processing residual risk.
2024 Quality Digest. Copyright on content held by Quality Digest or by individual authors. Contact Quality Digest for reprint information.
Quality Digest" is a trademark owned by Quality Circle Institute Inc.