Relationship of DFMEA and PFMEA
As you know the DFMEA is the risk analysis tool and covers the risk of Design Failure.
PFMEA is also a risk analysis tool that covers the risk of Process Failure.
In the development cycle, we start from the concept phase. We first finalize our design. Then we do prototype validation—then the actual manufacturing process development and then final production.
Now, if you have a failure in your manufacturing process.
It will lead to the production of defective products. Once the product is not as per specification it leads to fail its function.
This clearly shows the relationship between process failure will lead to product failure.
In the FMEA we do the failure analysis as Failure cause, failure Mode, and Failure effect.
So, the PFMEA failure effects are nothing but the DFMEA failure.
This means Process failures and Design Failures are interlinking together.
How to link DFMEA and PFMEA together?
The DFMEA and PFMEA link together with the topics below,
In the Design FMEA, the failure cause is product characteristics fail. Then the failure mode will be Design function fail and the failure effect will be system failure or Failure at the end user.
Now in the Process FMEA (PFMEA) failure cause is your process characteristics failure.
The failure mode can be your Product Characteristics Failure and the failure effects are at three level
- PFMEA failure effects are at Plant,
- at Ship-to-plant or at the Customer end and
- at the End-user level.
So, the failure effects of the customer/system/End-user are coming from the DFMEA Failure Effects.
lf the DFMEA failure effects are the same for PFMEA failure effects, then the severity is also the same and transferred as it is to the PFMEA.
Do you know, the purpose of the same severity from DFMEA to PFMEA is to communicate and integrate the same risk impact throughout the operation cycle from Customer to supplier to Sub-supplier.
And it is also one of the outputs of FMEA.
These special characteristics will further be considered as input for the Control Plan.
In the Design FMEA, we consider the product characteristics and identify the SC & CC characteristics.
To control those product characteristics, In the process FMEA we identify the Process Characteristics.
Now you understand the relationship between DFMEA and PFMEA.
You must consider those points in your study to align both documents.
Further, the output will help to create the control plan as well. The same strong relation you can see in between PFMEA and Control Plan.
Hope this article will help you. Write us on other topics you want the detailed article for.