Severity in Process FMEA for Rework Process

[gaurav16949]

Hello all
I am having confusion about severity ranking in Process FMEA. Please consider the example discussed below

In trimming process, the failure mode identified is Total Length Over Size and its effects of failure identified are a) Rejection of components b)Re-work of components on-station with severity 8 and 4 respectively.

So as per the FMEA manual value of severity has to be provided as per worst case which is rejection of the components with severity 8.

So is there any example where we can use severity 3,4,5,6 from second table of severity for rework of components on station or off-station. What i feel is if we will do rework it means the component is non-confirming, if component is non-confirming then due to worst case statement a) as discussedin example the severity is to be considered as 8.

Thanks in advance for your valuable time and response

Gaurav Kumar

 

[Zbigniew Huber]

Hello,

For manufacturing related effects I recommend to use following approach:
(Consider severity = financial impact for your company)

8 - line shutdown, 100% production scrap (high financial loss $$$$$$$$)
7 - part of production lot scrap ($$$$$$$)
6 - 100% production rework/repair at separate workstation ($$$$$)
5 - part of production lot rework/repair at separate workstation ($$$$)
4 - 100% production rework/repair "in station" (where failure occurs) ($$$)
3 - part of production lot rework/repair "in station" (where failure occurs) ($$)
2 - extra effort for operator "in station" ($)
1 - no effects

So I suggest applying 5 or 6 for offline rework operations.