-
- News
- Books
Featured Books
- pcb007 Magazine
Latest Issues
Current IssueFueling the Workforce Pipeline
We take a hard look at fueling the workforce pipeline, specifically at the early introduction of manufacturing concepts and business to young people in this issue of PCB007 Magazine.
Inner Layer Precision & Yields
In this issue, we examine the critical nature of building precisions into your inner layers and assessing their pass/fail status as early as possible. Whether it’s using automation to cut down on handling issues, identifying defects earlier, or replacing an old line...
Engineering Economics
The real cost to manufacture a PCB encompasses everything that goes into making the product: the materials and other value-added supplies, machine and personnel costs, and most importantly, your quality. A hard look at real costs seems wholly appropriate.
- Articles
- Columns
Search Console
- Links
- Media kit
||| MENU - pcb007 Magazine
Happy’s Essential Skills: Failure Modes and Effects Analysis (FMEA)
April 6, 2016 | Happy HoldenEstimated reading time: 12 minutes

What is FMEA?
Failure modes and effects analysis (FMEA) is a systematic process to evaluate failure modes and causes associated with the design and manufacturing processes of a new product. It is somewhat similar to the potential problem analysis (PPA) phase of the Kepner-Tregoe program. Here is a list of activities for a FMEA:
1. Determine potential failure modes of each component or subassembly and causes associated with the designing and manufacturing of a product.
2. Identify actions which could be eliminate or reduce the chance of a potential failure occurring.
3. Document the process and give each mode a numeric rating for frequency of occurrence, criticality, and probability of detection.
4. Multiply these three numbers together to obtain the risk priority number (RPN), which is used to guide the design effort to the most critical problems first.
Two aspects of FMEA are particularly important: a team approach and timeliness. The team approach is vital because the broader the expertise that is brought to bear on making and assigning values to the failure mode list, the more effective the FMEA will be.
Timeliness is important because FMEA is primarily a preventive tool, which can help steer design decisions between alternatives before failure modes are designed-in, rather than redesigning after the failure occurs. FMEA is equally applicable to hardware or software, to components or systems.
Comparison to FTA
Another similar process is fault tree analysis (FTA). While FMEA is a bottom-up approach, FTA is top-down. FTA starts with the assumption of a system failure mode, and then works down through the system block diagram to look for possible causes of that mode.
Thus, FTA requires fairly complete, detailed information about the system, and is most effective after the system is well-defined. (FTA could be performed, in a limited way, on alternative system concepts; this could be used to help decide the best of several alternatives.) A separate FTA must be performed for each system failure mode.
FTA and FMEA are complimentary. Whenever possible, both should be used. For practical reasons, FTA should be limited to the really serious system-level failure modes, such as those involving safety or permanent system damage. FMEA can be used at the component, subassembly, and module level, to help optimize those modules. There are excellent discussions and examples of FTA in References 2 and 4, and it will not be discussed further in this column.
Benefits of FMEA
The RPN calculated by FMEA allows prioritization of the failure mode list, guiding design effort to the most critical areas first. It also provides a documentary record of the failure prevention efforts of the design team, which is helpful to management in gauging the quality and extent of the effort, to production in solving problems which occur despite these efforts, and to future projects which can benefit from all the work and thinking that went into the failure mode and cause lists.
Eliminating potential failure modes has both short term and long term benefits. The short term benefit is most often recognized because it represents savings of the costs of repair, retest, and downtime, which are objectively accountable. The long term benefit is much more difficult to measure, since it relates to the customer satisfaction or dissatisfaction with the product, and perception of its quality.
FMEA supports the design process by:
- Aiding in the objective evaluation of alternatives during design
- Increasing the probability that potential failure modes and their effects on system operation have been considered during design
- Providing additional information to aid in the planning of thorough and efficient test programs
- Developing a list of potential failure modes ranked according to their probable effect on the customer, thus establishing a priority system for design and test
- Providing an open, documented format for recommending and tracking risk-reducing actions
- Identifying known and potential failure modes which might otherwise be overlooked
- Exposing and documenting the ways a system can fail, and the effects of such failures
- Detecting primary but often minor failures which may cause serious secondary failures or consequent damage
- Detecting areas where "fail safe" or "fail soft" features are needed
- Providing a fresh viewpoint in understanding a system's functions
The uses of a FMEA report include:
- A formal record of the safety and reliability analysis and planning, to satisfy customers or regulatory agencies
- Evidence in litigation involving safety or reliability
- Design of diagnostic routines or built-in tests
- A basis for creating trouble-shooting procedures
- A means to consider and prevent manufacturing defects
- Problem follow-up and corrective action tracking
- A future reference to aid in analyzing field failures, evaluating design changes, or developing improved designs
Page 1 of 5
Suggested Items
Qorix, Qualcomm Cooperate to Drive the Future of Software-Defined Vehicles
02/07/2025 | Qualcomm Technologies, Inc.Qorix, a global provider of modular and integrated automotive middleware solutions, and Qualcomm Technologies, Inc., a leader in automotive platforms, announced a technology cooperation to help drive the future of software-defined vehicles (SDVs) with high performance, pre-integrated and scalable solutions designed to enable OEMs and tier-1 suppliers to develop next generation vehicles quickly and efficiently.
Dan Beeker on the Design Engineer of the Future
02/07/2025 | Andy Shaughnessy, Design007 MagazineAs technical director at NXP Semiconductors, Dan Beeker specializes in EMC and signal integrity design techniques. He’s known for his field-based design classes; you may remember the cover of Meghan Trainor’s “All About That Bass” that Dan and his daughter Breezy released in 2015 titled “All About The Space.” Check it out on YouTube; it’s funny, and it definitely gets the point across. As we begin 2025, I contacted Dan to get his thoughts about the design engineers of the future. What will their jobs look like?
SFL Missions Awarded Canadian Space Agency Contract for HAWC Satellite Mission Conceptual Design Study
02/07/2025 | BUSINESS WIRESFL Missions Inc. has been awarded a competitive bid contract by the Canadian Space Agency (CSA) to conduct a conceptual design study of the planned High-Altitude Aerosols, Water vapour, and Clouds (HAWC) satellite mission. HAWC is Canada’s contribution to NASA’s Atmosphere Observing System (AOS) mission slated for launch in 2031.
I-Connect007 Editor's Choice: Five Must-Reads for the Week
02/07/2025 | Marcy LaRont, I-Connect007For my top picks this week, I wanted to highlight some other important content we’ve featured. First is the incomparable Stephen Chavez, who provides insight into what the future PCB designer will look like. Bob Duke of American Standard outlines the seven key challenges he sees in offshore manufacturing. We move seamlessly from there to tariffs, one of today’s most talked about topics. Jeffrey Beauchamp of NCAB looks back at a recent timeline regarding tariffs, and it’s quite interesting. I’m also pointing you toward a feature on a thriving EMS company in Malaysia, one of the two most popular locations for China Plus One manufacturing expansions. Finally, we acknowledge the expansion news of a long-time PCB and EMS global supplier.
First Pan-European Electronics Design Conference (PEDC) in Vienna Inspires Participants from 20 Countries
02/06/2025 | IPCThe first Pan-European Electronics Design Conference (PEDC) in Vienna was a great success The new international conference, organized by Fachverband Elektronikdesign und -fertigung e. V. (FED) and IPC, brought together experts and industry representatives from 20 countries and four continents.