This Month's Theme is Discussing the Controversial Issue of FMEA Pre-population
Next month's theme will be using FMEAs to improve design verification plans
Every month in FMEA Corner, join Carl Carlson, a noted expert in the field of FMEAs and facilitation, as he addresses a different FMEA theme (based on his book Effective FMEAs) and also answers your questions.
Questions and answers are a great way to learn about FMEAs, for both experienced and less experienced FMEA practitioners. Please feel free to ask any question about any aspect of FMEAs. Send your questions to Carl.Carlson@EffectiveFMEAs.com, and your contact information will be kept anonymous. All questions will be answered, even if they are not featured in the FMEA Corner.
pre·pop·u·late [pre·pop·yuh·leyt, verb]
To "pre-populate" is "to populate (form fields, a database) in advance." The Oxford English Dictionary defines "populate" as "add data to a previously empty section of (an electronic form, document)."
FMEAs have many well-known benefits, when done properly. One of the challenges for FMEA teams is to conduct their assigned FMEAs within the time available during the product development process. FMEA is a team-based activity, and subject matter experts have many tasks competing for their limited time. As a result, in the real-world application of FMEA, some companies are compelled to consider pre-populating selected portions of the FMEA. The purpose of this article is to discuss the benefits and downsides of FMEA pre-population.
What is meant by pre-populating an FMEA?
Some companies consider entering selected information into the FMEA worksheet before the first team meeting. Such entries are examples of "pre-populating an FMEA."
One example of pre-population is entering function descriptions. These can be extracted from technical specifications or from individual subject matter experts, and entered into the Function column.
Another example is historical problems for similar items. These can be obtained by analyzing historical field or manufacturing failures, and entered in the Potential Failure Mode column.
Any information that is pre-populated in one of the FMEA columns should be considered preliminary and must be reviewed and revised as needed by the entire FMEA team before finalizing.
What are the pros and cons of FMEA pre-population?
Care must be exercised when considering pre-populating any portion of the FMEA. There are potential benefits and potential downsides to pre-population, and the team should be fully aware of the benefits and downsides.
The obvious benefit of pre-populating selected portions of an FMEA is to save in-meeting time of subject matter experts (SMEs). SME time is valuable and any time that can be saved is beneficial, provided that it does not compromise the integrity of the FMEA.
The downside to pre-populating selected portions of an FMEA is the potential for incorrect or missing important information in the final FMEA. FMEA is a team-based activity and when portions of the FMEA are pre-populated, there is the chance that the results could be compromised.
The following is an excerpt from the February 2015 FMEA Corner:
The only way that pre-population of selected portions of the FMEA can work, without losing value, is if the FMEA facilitator and team pay attention to these three reasons and ensure they are addressed. Let's take them up one by one.
Reason # 1: Blind spots:
When information is pre-populated in an FMEA, the person doing the pre-population may have "blind spots," and include incorrect information or miss important information. When the pre-populated information is subsequently reviewed with the FMEA team, care must be taken to ensure that the team detects incorrect or missing information. Good facilitation will mitigate this potential issue.
Reason # 2: Correct team:
As mentioned above, FMEAs require the correct team representation in order to be effective. This is also essential when reviewing pre-populated information. The full team must be present when reviewing pre-populated information in order to be sure there is no incorrect or missing information.
Reason # 3: Cross talk and synergy:
Also as covered above, one of the indispensable values of an FMEA is the cross talk and synergy between subject matter experts that occurs during the meetings. The team should avoid deferring to the person who pre-populated the information. In other words, the team should assume there are errors in the pre-populated information and attempt to find the errors. In essence, the FMEA team must discuss and thoroughly examine the pre-populated information. Otherwise, one of the primary benefits of the FMEA exercise can be missed.
It is a human shortcoming that when people look at lists of information, they sometimes fail to see what is missing in the set of information. It is easier to correct or modify what you see than it is to see what is not there.
When reviewing pre-populated information, it is essential that the FMEA team is empowered and encouraged to look with a critical eye.
Pre-populating selected FMEA columns
Some columns of the FMEA lend themselves to pre-population more than other columns. In this section of the article, we will consider the possibility of pre-populating selected portions of functions, failure modes and controls, along with suggestions for avoiding the downsides to pre-population of these columns.
It may be possible for someone to pre-populate the functions in the FMEA. Examination of the product and technical specifications, as well as consulting with SMEs, can provide input to the function descriptions. When pre-populating the primary functions in an FMEA, ensure that the function descriptions are exactly according to definition, including the standard of performance. Review with the full FMEA team to modify function descriptions or add missing functions. Make sure that the team is tasked with correcting any deficiencies.
Pre-populating historical Failure Modes:
It may be possible to pre-populate historical failure modes based on actual field history (in the case of System or Design FMEAs) or manufacturing history (in the case of Process FMEAs). Some practitioners survey individual SMEs to determine potential failures of concern. Past FMEAs may provide insight into potential failures for new designs. When failure modes are pre-populated, these will need to be reviewed with the entire team to modify failure mode descriptions or add missing failure modes.
Pre-populating Detection Controls:
It may be possible to pre-populate detection-type controls in an FMEA. This can only be considered after the FMEA has been completed up through failure modes and causes because detection-type controls are associated with the corresponding failure modes and causes. Current and past test plans and test procedures are considered when deciding what information to pre-populate in the detection controls column. As covered before, these will need to be reviewed in detail with the entire FMEA team to ensure that nothing is missed and incorrect detection controls are modified.
Pre-population using Xfmea
One way to visually show the status of pre-population in an FMEA is to add a column to the FMEA worksheet.
In the example of pre-populating functions, it may be useful to add a Status column next to the Function column. This can be a drop-down list with "preliminary" and "final" as choices.
Choose FMEA > Tools > Configurable Settings to open the FMEA Properties window. Select the Functions page, then enable the "Function User Drop-Down 1" field and change the display name to "Status." Modify the drop-down list to add "Preliminary" and "Final" as options, then close the FMEA Properties window. Switch to the worksheet view and move the Status field next to the Function field. You will see something that looks like this.
FMEA Tips of the Month
Tip 1: Pre-populated information can be assigned a status such as "preliminary." That way the FMEA facilitator can be sure the information is thoroughly reviewed with the FMEA team before changing the status to "final."
Tip 2: Some companies use a "seen/unseen" column next to failure modes to identify field failures that are pre-populated in the FMEA. That way the FMEA team can be sure that past field failures are considered, and can be sure that they will not occur in the new designs.
Tip 3: Another suggestion to avoid potential downsides to pre-population is to begin FMEAs with identifying major areas of concern. Refer to the October 2015 FMEA Corner for ideas and suggestions.
By beginning with individual areas of concern, the FMEA team records the primary concerns of the SMEs, and when the team reviews subsequent pre-populated columns, they can be sure that no primary concerns go unaddressed.
While it is true that pre-populating selected information in an FMEA can save valuable time, there are potential downsides to pre-population. Where companies are compelled to consider pre-population of selected portions of FMEAs due to limited availability of subject matter experts, the FMEA facilitator and team need to understand the downsides and use mitigation strategies to ensure that the integrity and value of the FMEA is fully realized.
I’ve always wanted to know about FMEAs
The important thing is not to stop questioning. - Albert Einstein
A HotWire reader submitted the following question to Carl Carlson. To submit your own question about any aspect of FMEA theory or application, e-mail Carl at Carl.Carlson@EffectiveFMEAs.com.
If, for high risk issues, the FMEA team will include defined root cause at the failure mechanism level in the description in the Cause column of System DFMEA, wouldn't it make FMEA too complicated? I mean a case when e.g. there are several root causes for one system failure mode, indeed we should include descriptions of all of them in that column.
Carl: Before answering your question, I'll show an excerpt from my book (Figure 3.2 on page 31) that illustrates the progression from System FMEA down to component FMEA, including root cause and failure mechanism.
It is true that for high-risk issues, FMEAs need to get to root cause and failure mechanism. However, this does not mean the System FMEA must take all high-risk issues to root cause and failure mechanism. When the System FMEA team identifies a high-risk issue, they need to recommend the actions that will address the risk and document these actions in the Recommended Actions column. This can include recommending a lower-level FMEA in order to get to root cause and failure mechanism. As you point out, to drill down to root cause on each issue in the System FMEA could create an exceptionally large document. The preferred procedure is to selectively move lower in the system hierarchy, based on risk, in order to properly define the cause at the failure mechanism level for high-risk issues.
About the Author
Carl S. Carlson is a consultant and instructor in the areas of FMEA, reliability program planning and other reliability engineering disciplines. He has 35 years of experience in reliability testing, engineering and management positions, and is currently supporting clients from a wide variety of industries, including clients of HBM Prenscia. Previously, he worked at General Motors, most recently senior manager for the Advanced Reliability Group. His responsibilities included FMEAs for North American operations, developing and implementing advanced reliability methods and managing teams of reliability engineers. Previous to General Motors, he worked as a Research and Development Engineer for Litton Systems, Inertial Navigation Division. Mr. Carlson co-chaired the cross-industry team that developed the commercial FMEA standard (SAE J1739, 2002 version), participated in the development of SAE JA 1000/1 Reliability Program Standard Implementation Guide, served for five years as Vice Chair for the SAE's G-11 Reliability Division and was a four-year member of the Reliability and Maintainability Symposium (RAMS) Advisory Board. He holds a B.S. in Mechanical Engineering from the University of Michigan and completed the 2-course Reliability Engineering sequence from the University of Maryland's Masters in Reliability Engineering program. He is a Senior Member of ASQ and a Certified Reliability Engineer.
Selected material for FMEA Corner articles is excerpted from the book Effective FMEAs, published by John Wiley & Sons, ©2012. Information about the book Effective FMEAs, along with useful FMEA aids, links and checklists can be found on www.effectivefmeas.com. Carl Carlson can be reached at email@example.com.