To Prepopulate or not to prepopulate, that is the question
By prepopulating the highest priority functions, along with other selected information, the FMEA team can focus their efforts on the most important functions, and minimize in-meeting time. This is the last step in FMEA preparation. However, there are specific limitations to FMEA prepopulation that must be understood and adhered to.
“Give me six hours to chop down a tree and I will spend the first four sharpening the axe.”
The definition of “prepopulate” 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).
What is meant by prepopulating an FMEA?
Some companies consider entering selected information into the FMEA worksheet before the first team meeting. Such entries are what are meant by prepopulating an FMEA.
One example of prepopulation 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 prepopulated 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 prepopulation?
Care must be exercised when considering prepopulating any portion of the FMEA. There are potential benefits and potential downsides to prepopulation, and the team should be fully aware of the benefits and downsides.
The obvious benefit of prepopulating 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 it does not compromise the integrity of the FMEA.
The downside to prepopulating 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 prepopulated, there is the chance that the results could be compromised.
Excerpting from my book, Effective FMEAs:
There are three primary reasons for the necessity to have the correct team when doing an FMEA.
1. People have “blind spots.” A well-defined cross-functional team minimizes the errors inherent with “blind spots.”
2. The FMEA analysis requires subject matter experts from a variety of disciplines to ensure incorporation of all necessary inputs into the exercise, and that the proper expertise is applied to the design or process being analyzed.
3. One of the indispensable values of an FMEA is the cross talk and synergy between subject matter experts that occurs during the meetings. Well-defined groups can discover things that individuals often miss.
The only way that prepopulation 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 prepopulated in an FMEA, the person doing the prepopulation may have “blind spots”, and include incorrect information or miss important information. When the prepopulated 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 covered in the excerpt referenced above, FMEAs require the correct team representation, in order to be effective. This is also essential when reviewing prepopulated information. The full team must be present when reviewing prepopulated information in order to be sure there is no incorrect or missing information.
Reason # 3: Cross talk and synergy:
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 prepopulated the information. In other words, the team should assume there are errors in the prepopulated information and attempt to find the errors. In essence, the FMEA team must discuss and thoroughly examine the prepopulated 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 prepopulated information, it is essential that the FMEA team is empowered and encouraged to look with a critical eye.
What elements of an FMEA can be prepopulated?
Where prepopulation has been done successfully in companies, it has been limited to selected portions of functions, failure modes and controls. Here are suggestions to avoid the downside to prepopulation.
It may be possible for someone to prepopulate the functions in the FMEA. Examination of product and technical specifications, as well as consulting with SMEs can provide input to the function descriptions. When prepopulating the primary functions in an FMEA, ensure the function descriptions are exactly according to definition, including standard of performance. Review with the full FMEA team to modify function descriptions or add missing functions. Make sure the team is tasked with correcting any deficiencies.
Prepopulating historical Failure Modes:
It may be possible to prepopulate 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 prepopulated, these will need to be reviewed with the entire team to modify failure mode descriptions or add missing failure modes.
Prepopulating Detection Controls:
It may be possible to prepopulate detection-type controls in an FMEA. This can only be considered after the FMEA has been completed up through failure modes and causes. The reason for this is the 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 prepopulate in the detection controls column. As covered before, these will need to be reviewed in detail with the entire FMEA team to ensure nothing is missed and incorrect detection controls are modified.
One way to visually show the status of prepopulation in an FMEA is to add a “Status” column to the FMEA worksheet. Here is what it looks like.
Another way to visually show the status of prepopulation in an FMEA is to add an asterisk at the end of prepopulated entries. Here is what it looks like.
Tip 1: Prepopulated 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 prepopulated in the FMEA. That way the FMEA team can be sure that past field failures are considered, and can be sure they will not occur in the new designs.
Tip 3: Another suggestion to avoid potential downsides to prepopulation is to begin FMEAs with identifying major areas of concern. By beginning with individual areas of concern, the FMEA team records the primary concerns of the SMEs, and when the team reviews subsequent prepopulated columns, they can be sure that no primary concerns go unaddressed.
Prepopulating selected information in an FMEA can save valuable time, and help ensure successful FMEA application. However, there are potential downsides to prepopulation, and the FMEA facilitator and team need to understand the downsides and use mitigation strategies to ensure the integrity and value of the FMEA is fully realized.
This completes the “FMEA Preparation” series. Click on FMEA Resources to see the complete set of articles in the “FMEA Fundamentals” series and the “FMEA Preparation” series.
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.
Before answering your question, I’ll show an excerpt from my book (Figure 3.2 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. To drill down to root cause on each issue in the System FMEA will create an exceptionally large document, as you point out. The preferred procedure is to selectively move lower in the system hierarchy in order to identify root cause and failure mechanism for all high-risk issues.
This completes the series of articles on FMEA Preparation. The next series of articles will cover special topics that help bring about effective FMEAs. The first article in this series will be on the application of failure mechanisms in FMEA. Properly understanding and applying failure mechanisms in FMEA will greatly enhance the effectiveness of cause descriptions and better enable actions to reduce risk.
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