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Design FMEA Form

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Click here for excel form

Description of Form

Part/Assembly Name - Enter the whole name as shown on the part drawing.

Part/Assembly Number - Enter the whole number as shown on the part drawing. Include revision identifications.

Engineer - Enter the full name of the person who drafts the FMEA form. This person is usually the engineer responsible for the product's development and release to manufacturing.

Customer/Application/Other - Enter the name of the customer, all applications where the product is to be used, or any other information relevant to the scope of the FMEA.

Vendor Name - Identify the supplier(s) when components or systems are purchased.

Scheduled Production Release Date - Enter the date the product is to be released for production.

FMEA Number - Enter a sequential number to identify the FMEA. This may be obtained from the FMEA facilitator.

Page - Enter as indicated.

Dates - Enter the date the page was worked on. Enter revision dates on the revised pages, as well as the first page.

Function(s) and Specification - Describe the function the part is to perform and the specification it is to meet. Make the description as clear and concise as possible. Be sure to include all functions. If the part performs more than one function, and the functions differ greatly, it may be desirable to complete a separate FMEA form for some. Include pertinent information about the product specification, such as the forces involved, the operating environment, and so on. Otherwise, the review team may fail to fully understand the part's function and miss a potential failure mode.

Potential Failure Modes - For ideas on potential failure modes, use personal experience, engineering judgment, quality and warranty reports, litigation case histories, and so on.

Potential Effects of Failure Mode on End Product and End User - The potential effect is what the end user might experience as a result of the failure mode. List all conceivable effects, including violations of government regulations. Group together any effects that are similar or have equal severity.

Severity - A subjective estimate of how severe the end user will perceive the effect of the failure to be. Based on a scale of 1 to 10, shown:

Ranking	Criteria
1	Negligible severity. It is unreasonable to think that this effect would impact the product's performance. The end user will probably not notice any defect.
2 and 3	Mild severity. The effect would cause only a slight annoyance. The end user will not notice any performance change. Repair can be done at the time of regular maintenance.
4, 5, and 6	Moderate severity. The end user will notice tolerable degradation in performance or appearance. Repair is inexpensive, downtime short.
7 and 8	High severity. The end user will notice an intolerable effect. The effect will occur without warning to an untrained person. Downtime is expensive. Degradation in areas subject to government regulations, but not involving safety.
9 and 10	Potential safety problems. Dangerous effects which occur without warning. Nonconformance to laws.

Note: Avoid assigning more than three different severity rankings to the effects of one failure mode. This facilitates the ranking of likelihood.

Potential Causes of Failure - The potential cause of a design-related failure mode is a design weakness, such as inadequate strength; unsuitable material; incomplete design specification; too refined machining and/or assembly requirements; possibility of maladjustment due to poor accessibility for servicing; vague instructions; misuse; incompatibility with working media; wear; overload; stress; corrosion; missing instructions on drawings, and so on.

The majority of causes listed should be design-related. Occasionally, however, a cause may be manufacturing-related (out-of-print part) or service-related (instructions not followed). For convenience and clarity, all design-related causes should be grouped together, followed by manufacturing- and service-related ones.

Likelihood - A subjective estimate of the probability that the cause, if it occurs, will produce the failure mode and its particular effect. Based on a scale of 1 to 10, shown:

Ranking	Criteria
	Verbal	Defect Rate
1	It is unlikely that this cause would result in the failure mode.	1 in ____
2 and 3	The failure would occur only under rare circumstances.	1 in ____
4, 5, and 6	Failure is somewhat likely.	1 in ____
7 and 8	Failure is very likely.	1 in ____
9 and 10	Almost certain that a failure will occur.	1 in ____

Note: The defect rate that is appropriate for each ranking will vary depending on the product.

Likelihood applies to the effect of a failure mode, too, since every failure mode produces at least one effect. So, for every effect, or group of similar effects, there should be a corresponding likelihood ranking.

Example A: 1 failure mode, 1 cause, 2 effects
A part could potentially break under a certain overload, which produces two effects: a minor one and a major one. In FMEA terminology, this translates into:
Potential failure mode: break
Potential cause: overload
Potential effect: minor effect and major effect
First, the overall likelihood ranking is estimated. The overload is very likely to result in a break, so the overall likelihood ranking would be 8. This is not recorded on the FMEA form.
Next, the likelihood of the failure mode resulting in each effect is estimated. These rankings cannot exceed the overall likelihood ranking of 8. Therefore, the top of the scale temporarily shrinks from 10 to 8. The minor effect is more likely to occur than the major one, so it would rank 6 on the new scale. The major effect is rarely encountered and so would rate a 1. These numbers are recorded on the FMEA form, one above the other, in the same order in which the effects are listed.

Example B: 1 failure mode, 1 cause, 3 effects
Follow the same procedure as in Example A, using an appropriately "shrunken" scale.
For clarity, it is recommended that all three likelihood rankings be entered, even if some are the same. There should be at least as many likelihood rankings for each cause as there are severity numbers. If the severity ranking is the same for all three effects (only one number appears in the severity column), then there may be one or more likelihood rankings.

Example C: More than 3 effects
When there are more than three individual effects, it is sometimes possible to group them together into three or fewer groups. In each group, the effects are similar with respect to severity and likelihood.

Example D: Diversified effects
When there are so many and/or so diversified effects that, even after grouping, more than three groups remain, it is recommended that separate FMEA forms be completed for the excess effects.

In-Place and Planned Cause Preventions or Detections - Identify the measures established to prevent or detect the cause of the failure mode. Examples: product specification, test and calculation reports, inspection and manufacturing specifications, service instructions, information on the engineering drawing, and so on. Include measures that are not yet implemented, as long as they are definitely planned.

Effectiveness - A subjective estimate of how effectively the prevention or detection measure eliminates potential failure modes. It quantifies judgment of the soundness of a design feature or inspection procedure, the validity of a test, the sufficiency of a final test, and so on. Based on a scale of 1 to 10, shown:

Ranking	Criteria
	Verbal	Rate of Cause Occurrence
1	The prevention or detection measure is foolproof. There is no chance that the cause might still occur.	1 in ____
2 and 3	The likelihood of the cause occurring is low.	1 in ____
4, 5, and 6	Moderate likelihood. The prevention or detection method allows the cause to occur occasionally.	1 in ____
7, 8, and 9	High likelihood. The prevention or detection method is effective only sometimes; the cause occurs repeatedly.	1 in ____
10	Very high likelihood. The prevention or detection measure is ineffective. The cause will occur.	1 in ____

Note: The rate of occurrence that is appropriate for each ranking will vary depending on the product.

Risk Priority Number - The Risk Priority Number (RPN) is the product of the severity, likelihood and effectiveness rankings. For example:

Severity	Likelihood	Effectiveness	RPN
8	9	2	144

Every failure mode has an RPN. By rank ordering the RPNs, it is possible to determine which failure mode is most critical and assign it priority for corrective action. If there is more than one likelihood number associated with a particular cause, then there should be an equal number of RPNs. Enter them all, or just their average, or both.

Recommended Actions to Eliminate Cause or to Enhance Prevention or Detection - Enter recommendations for reducing the likelihood that a failure mode will occur, or for improving the effectiveness of the prevention or detection methods. Recommendations for improving severity are appropriate here, too; however, they will always involve a design change.

Responsibility for Action Accepted by - Enter the name of the individual on the FMEA review team who has the authority to implement the corrective action.

Action Priority - Assign priorities to the recommended corrective actions by considering the RPN and other factors. High priority should always be given to corrective actions associated with failure modes of high severity. Shown below is one method of classification:

Priority Classification	Description
A	Action must be implemented before shipments begin.
B	Action must be initiated or resolved or implemented within a month.
C	Action must be initiated or resolved or implemented within a year.
D	Action may or may not be pursued.
---	Action will not be pursued.