I was reading this slide:
http://Elsmar.com/FMEA/sld024.htm
What do You think about this relationship?
Sometimes I see this relationship.
But Can I see it as a Rule?
At the outset, something that I learnt through this very forum and realized practically too is - in
FMEA going by 'rules' will some times defeat the purpose of doing FMEA. As long as the purpose of
the FMEA is met which is Risk identification, followed by prioritization, followed by mitigation, I do not mind violating any written rule, guideline, process step, Manual reference whatsoever. While there definitely must be a guideline or rule in place to help the FMEA team have consistent approach, use of such guideline shall not be enforced at the cost of value propagation the FMEA will add otherwise.
As for the relationship part, the causes in
DFMEA are basically in the category of typical design cause, interface causes due to surrounding components, causes by virtue of changes over time like aging, wear/tear, etc, causes due to external environment, Customer use, and then causes due to manufacturing variation and manufacturability. Manufacturing variation of course has direct relevance to process design. And all other design causes do give significant 'inputs' to failure mode in
PFMEA rather than becoming a failure mode themselves in PFMEA. It is important for PFMEA team to listen to these causes in the context of its effect and controls identified in DFMEA along with relevant historical data before moving any further.