PFMEA Severity Rankings
PFMEA Occurrence Rankings
ProbabilityLikely Failure RatesPpkRankingVery High: Persistent
Failures100 per thousand pieces50 per thousand pieces< 0.55>
0.55109High: Frequent Failures20 per thousand pieces10 per thousand
pieces> 0.78> 0.8687Moderate: Occasional Failures5 per
thousand pieces
2 per thousand pieces
1 per thousand pieces> 0.94
>1.00
>1.106
5
4Low: Relatively Few Failures0.5 per thousand pieces
0.1 per thousand pieces>1.20
> 1.303
2Remote: Failure is unlikely< 0.001 per thousand pieces *>
1.671Note: Identical to Manual except for Ranking of 1. Manual
allows for .01 per thousand (10 PPM)DELPHI Supplier Quality FMEA
OCCURRENCE EVALUATION RANKINGSSample calculation to determine Ppk
value from a likely failure rate of 5 per thousand pieces (see FMEA
third Appendix I).
PFMEA Detection Rankings
RankingEffectPFMEA10Absolute UncertaintyCannot detect or is not
checked.9Very RemoteControl is achieved with indirect or random
checks only.8RemoteControl is achieved with visual inspection
only.7Very LowControl is achieved with double visual inspection
only.6LowControl is achieved with charting methods, such as SPC
(Statistical Process Control) OR gauging performed on setup and
first-piece check. *5ModerateControl is based on variable or
attribute gauging performed 100% of the parts after parts have left
the station.4Moderately HighError detection in subsequent
operation. *3HighError detection in-station, or error detection in
subsequent operations by multiple layers of acceptance: supply,
select, install, verify. Cannot accept discrepant part.2Very
HighError detection in-station (automatic gauging with automatic
stop feature). Cannot pass discrepant part.1Almost
CertainDiscrepant parts cannot be made because item has been
error-proofed by process/product design.* Note: Identical to Manual
except for Rankings of 6 and 4. Words OR gauging performed on setup
and first piece check moved from a detection of 4 to a detection of
6DELPHI Supplier Quality FMEA Detection Rankings
MBD001AC6F1.docDELPHI Supplier Quality FMEA SEVERITY
RANKINGS
Note #1: Any Failure Mode affecting the Vehicle Assembly Plant
MUST be ranked an 8 or higher.
Note #2: Any Failure Mode affecting a Delphi Plant MUST be
ranked 5 or higher.
Select from the categories below, using the highest applicable
ranking.
Ranking
Effect
End Customer
Vehicle Assembly Plant
Delphi Plant
Supplier Plant
10
Hazardous-without warning
Potential failure mode affects safe vehicle operation and/or
involves noncompliance with government regulation without
warning.
Potential failure mode may cause unsafe condition for plant
personnel without warning.
Potential failure mode may cause unsafe condition for plant
personnel without warning.
Potential failure mode may cause unsafe condition for plant
personnel without warning.
9
Hazardous-with warning
Potential failure mode affects safe vehicle operation and/or
involves noncompliance with government regulation with warning.
Potential failure mode may cause unsafe condition for plant
personnel with warning.
Potential failure mode may cause unsafe condition for plant
personnel with warning.
Potential failure mode may cause unsafe condition for plant
personnel with warning.
8
Very High
Vehicle/item inoperable (loss of primary function); failure mode
may cause customer walk home, field return, or durability
issue.
Potential failure mode may cause a spill/major disruption,
repair, assembly difficulty, rework, or sorting at the Vehicle
Assembly Plant
Potential failure mode may cause a spill/major disruption at a
Delphi Plant.
7
High
Vehicle/item operable but at a reduced level of performance.
Customer very dissatisfied. Failure mode may cause vehicle repairs
at Dealer. Includes Noise issues (squeak/rattle).
See Note #1
Potential failure mode may cause repair, assembly difficulty,
rework, sorting at a Delphi plant.
6
Moderate
Vehicle/item operable but comfort/convenience item(s))
inoperable/not performing to customer expectation (e.g.. Noise)
See Note #1
Potential failure mode may cause special handling of components
at Delphi-S.
5
Low
Vehicle/item operable but comfort/convenience item(s) operable
at a reduced level of performance.
See Note #1
Potential failure mode may cause inconvenience to Delphi prior
to assembly.
4
Very Low
Fit and finish item does not conform. Defect noticed by most
customers.
See Note #1
See Note #2
3
Minor
Fit and finish item does not conform. Defect noticed by average
customers.
See Note #1
See Note #2
2
Very Minor
Fit and finish item does not conform. Defect noticed by
discriminating customers.
See Note #1
See Note #2
1
None
No effect.
See Note #1
See Note #2
LPHI-S FMEA DETTION RANKking
Effect
PFMEA
10
Absolute Uncertainty
Cannot detect or is not checked.
9
Very Remote
Control is achieved with indirect or random checks only.
DELPHI-S FMEA RANKINGS
k.bourassa
Revised: 11/12/01
