Need for current design or process control

Watermelonsg

Starting to get Involved
Hi all,

Today I received one DFMEA from supplier, and I noticed the content for the column of "current design method" is empty. The RPN for the corresponding row is very low(<50).
The question popped out of my mind is: what is the guideline for the input/provision of current design control method?
personally I think it is not necessary to have the control method when the RPN score is very low.
Is there a criteria or guideline telling ppl when we should specify the control method?

Thanks!
 

John Predmore

Trusted Information Resource
The RPN score is calculated AFTER an assessment of the elements of risk (S,O,D) of the current situation, not the reverse. While it is possible a person could do the assessment and the multiplication in his mind and decide the risk is low and no controls are needed, leaving the current control field blank fails to communicate the basis for the assessment and the reasoning behind a decision the current situation was sufficient. As the customer, I think you should ask for more explanation.
 

Miner

Forum Moderator
Leader
Admin
Today I received one DFMEA from supplier, and I noticed the content for the column of "current design method" is empty. The RPN for the corresponding row is very low(<50).
The question popped out of my mind is: what is the guideline for the input/provision of current design control method?
personally I think it is not necessary to have the control method when the RPN score is very low.
Is there a criteria or guideline telling ppl when we should specify the control method?
Lack of a design control means the Detection rating is automatically = 10. This means the only way to get an RPN < 50 would be the following combinations of SEV & OCC (4 x 1, 1 x 4, 3 x 1, 1 x 3, 2 x 2, 2 x 1, 1 x 2, or 1 x 1. Considering that a severity rating of 3 or 4 typically means an annoyance noticeable by most customers, I would be concerned about the lack of design controls for those combinations.
 
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