A Design or Concept FMEA is a systematic approach (used by the design responsible team), to assures that potential design failure modes and associated causes have been considered and addressed.

 
A PFMEA is a living document and needs to be reviewed and updated as new failure modes are discovered. A PFMEA is used to identify potential weak areas in the manufacturing and assembling process. Cross-functional teams should be organized to study each step of process for possible failure modes, effects of failures, and potential causes. Countermeasures must be provided for failure modes with high Risk Priority Numbers (RPN). Also, regardless of the resultant RPN, special attention must be given when the severity is high.

DFMEA Severity Ranking Table :

Design FMEA : Severity of Effect
Effect	Criteria	Ranking
Hazardous without warning	Very high severity ranking when a potential failure mode affects safe vehicle operation and / or involves noncompliance with government regulation without warning.	10
Hazardous with warning	Very high severity ranking when a potential failure mode affects safe vehicle operation and / or involves noncompliance with government regulation with warning.	9
Very High	Vehicle / item inoperable, with loss of primary function.	8
High	Vehicle/ item operable, but at reduced level of performance. Customer very dissatisfied.	7
Moderate	Vehicle / item operable, but Comfort / Convenience item(s) inoperable. Customer dissatisfied	6
Low	Vehicle / item operable, but Comfort / Convenience item(s) operable at reduced level of performance. Customer experiences some dissatisfaction.	5
Very Low	Fit & Finish / Squeak & Rattle item does not conform. Defect noticed by most customers.	4
Minor	Fit & Finish / Squeak & Rattle item does not conform. Defect noticed by average customers.	3
Very Minor	Fit & Finish / Squeak & Rattle item does not conform. Defect noticed by discriminating customers.	2

DFMEA Occurrence Ranking Table :

Probability of Failure	Possible Failure Rates	Ranking
Very High: Persistent Failures	>/= 100 per thousand vehicles/ items	10
	50 per thousand vehicles / items	9
High: Frequent Failures	20 per thousand vehicles / items	8
	10 per thousand vehicle / items	7
Moderate: Occasional Failures	5 per thousand vehicle / items	6
	2 per thousand vehicle / items	5
	1 per thousand vehicle / items	4
Low: Relatively Few Failures	0.5 per thousand vehicle / items	3
	0.1 per thousand vehicle / items	2
Remote: Failure is unlikely		1

DFMEA Detection Ranking Table :

	Design FMEA : Severity of Effect
Detection	Criteria	Ranking
Absolute Uncertainty	Design Control will not and / or cannot detect a potential cause /mechanism and subsequent failure mode; or there is no Design Control	10
Very Remote	Very remote chance that the Design Control will detect a potential cause / mechanism and subsequent failure mode	9
Remote	Remote chance that the Design Control will detect a potential cause / mechanism and subsequent failure mode	8
Very Low	Very remote chance that the Design Control will detect a potential cause mechanism and subsequent failure mode	7
Low	Low chance that the Design Control will detect a potential cause / mechanism and subsequent failure mode	6
Moderate	Moderate chance that the Design Control will detect a potential cause / mechanism and subsequent failure mode	5
Moderately High	Moderately high chance that the Design Control will detect a potential cause / mechanism and subsequent failure mode	4
High	High chance that the Design Control will detect a potential cause / mechanism and subsequent failure mode	3
Very High	Very high chance that the Design Control will detect a potential cause / mechanism and subsequent failure mode	2
Almost Certain	Design Control will almost certainly detect a potential cause / mechanism and subsequent failure mode	1