Z
Zbigniew Huber
Hi,
I?d like to ask you how to properly approach to identification of potential failure modes in PFMEA according to AIAG FMEA Rev.4.
Let?s consider brazing process of two pipes in air conditioning unit in a vehicle.
Approach 1:
Process step: 50. Brazing
Function: Braze pipes in induction device
Requirements: Solder alloy uniformly bonds both components with no cracks, pinholes or holes.
Failure mode: Holes in solder alloy
Effects: End user->Coolant leak, air conditioner non operable (6), Manufacturing->Scrap (7)
Severity: 7
Cause: Brazing time too short, incorrect setup program selected
Approach 2:
Process step: 50. Brazing
Function: Braze pipes in induction device
Requirements: Proper brazing time
Failure mode: Brazing time too short
Effects: Product effect: Holes in solder alloy, End user->Coolant leak, air conditioner non operable (6), Manufacturing->Scrap (7)
Severity: 7
Cause: Incorrect setup program selected
In my opinion the AIAG FMEA Rev.4 says Approach 1 is preferred due to following:
AIAG FMEA Rev.4 page 71:
The PFMEA development continues by identifying the requirement(s) for each process/function. Requirements are the outputs of each operation/step and relate to the requirements for the product. The Requirements provide a description of what should be achieved at each operation/step. The Requirements provide the team with a basis to identify potential failure modes.
AIAG FMEA Rev.4 page 112 (about linkage between PFMEA and Control Plan):
?Product Characteristics? portion of the Control Plan may be derived from the ?Requirements? portion of the ?Process Function/Requirements? column and the ?Process Characteristics? portion may be derived from the ?Potential Cause(s) of Failure Mode? column.
For me the requirements in the PFMEA are ?expected results? from the given operation (what we want to achieve when we complete the operation) and in the above example the product characteristic should be in the requirement for value added operations and process characteristic (brazing time) is related to the potential cause.
I understand that both approaches give similar results and someone could say that both are good, but I need to clarify this for a discussion with my colleagues and how to follow the AIAG FMEA manual.
Best Regards,
Zbigniew
I?d like to ask you how to properly approach to identification of potential failure modes in PFMEA according to AIAG FMEA Rev.4.
Let?s consider brazing process of two pipes in air conditioning unit in a vehicle.
Approach 1:
Process step: 50. Brazing
Function: Braze pipes in induction device
Requirements: Solder alloy uniformly bonds both components with no cracks, pinholes or holes.
Failure mode: Holes in solder alloy
Effects: End user->Coolant leak, air conditioner non operable (6), Manufacturing->Scrap (7)
Severity: 7
Cause: Brazing time too short, incorrect setup program selected
Approach 2:
Process step: 50. Brazing
Function: Braze pipes in induction device
Requirements: Proper brazing time
Failure mode: Brazing time too short
Effects: Product effect: Holes in solder alloy, End user->Coolant leak, air conditioner non operable (6), Manufacturing->Scrap (7)
Severity: 7
Cause: Incorrect setup program selected
In my opinion the AIAG FMEA Rev.4 says Approach 1 is preferred due to following:
AIAG FMEA Rev.4 page 71:
The PFMEA development continues by identifying the requirement(s) for each process/function. Requirements are the outputs of each operation/step and relate to the requirements for the product. The Requirements provide a description of what should be achieved at each operation/step. The Requirements provide the team with a basis to identify potential failure modes.
AIAG FMEA Rev.4 page 112 (about linkage between PFMEA and Control Plan):
?Product Characteristics? portion of the Control Plan may be derived from the ?Requirements? portion of the ?Process Function/Requirements? column and the ?Process Characteristics? portion may be derived from the ?Potential Cause(s) of Failure Mode? column.
For me the requirements in the PFMEA are ?expected results? from the given operation (what we want to achieve when we complete the operation) and in the above example the product characteristic should be in the requirement for value added operations and process characteristic (brazing time) is related to the potential cause.
I understand that both approaches give similar results and someone could say that both are good, but I need to clarify this for a discussion with my colleagues and how to follow the AIAG FMEA manual.
Best Regards,
Zbigniew
