PQC (Product Quality Characteristics) and PFMEA

[nitros1]

Hi greetings!!

I work in the automotive industry, my story for you guys is...


We mold plastic injected parts, which go into an assembly process, our clients requieres or states, in the assembly drawing PQC, which for him I understand are product quality characteristics.

Now, I know that being in the drawing, I must put them in the PFMEA, but given that they are all points in the surface of a plastic components in the form of x= y= z = and given that the assembly line has no way of measuring this points, my thoughts are that maybe a check in a GDT can be used.

My questions are:

If the manufacturing ( assembly line) process does not mess with those pqcs, should they still be considered in the Assembly process PFMEA?? How can I be sure?

Should they be considered, should they be considered only in the molding process requirements of the PFMEA since they are all points in the surface?

Since it is the assembly drawing that is requesting us this PQCS, is it correct if I consider them in the molding process part of the PFMEA??

I hope you can help thank you.

 

[Sebastian]

Ask these questions to your team involved in request for quotation and feasibility study.
Customer drawing is input to your process of designing and developing manufacturing process. You can't ignore marked characteristics. If specification is presented in form which does not match your intended/already used measurement system, you have to select other measurement system or transform specification in other form matching your measurement system. You will need to get customer's approval anyway.

 

[nitros1]

thanks, but Im affraid this does not clear my mind

 

[Sebastian]

I was focused on question of ability to measure product characteristics as defined on customer's drawing and did not answer detailed question in your post. Sorry.

FMEA manual page 70 and topic of linkage between process flow diagram and FMEA and especially "Deliverables" column in Figure IV.2 Example Process Flow Diagram on page 72 should answer your question.
If you link product characteristics to process steps, you will find that referred product characteristics (these with x,y,x) are not what you require from assembling process, so you wont consider it there, but in moulding where they are made.

This is a very general answer, as I do not know your process flow, your processes and lessons learned related to process failures.

Additional comment - control of product characteristic is not limited to inspection of product itself. Through PFMEA you can determine process characteristics affecting them as well and decide to control it additionally to product inspection, so it can happen, that some assembling process characteristics are affecting product dimensions, so PFMEA can change also in this area.