Redundancy in PFD and Control Plans?

[ramanbnv]

Hi,

I'm new to PPAP. I was going through the Process Flow Diagram and Control Plan formats. I just needed to know the reason for fields "Key Product Characteristic" and "Key control Characteristic" to be present in the PFD, since they are addressed in the Control Plan.

Regards,

Raman

 

[Jim Wynne]

Hi,

I'm new to PPAP. I was going through the Process Flow Diagram and Control Plan formats. I just needed to know the reason for fields "Key Product Characteristic" and "Key control Characteristic" to be present in the PFD, since they are addressed in the Control Plan.

Regards,

Raman

There is no requirement for those fields to be there in the PFD; they're put there in most APQP software packages, but there's nothing in the standards that requires it. In fact, unlike the control plan and FMEA forms, there is no prescribed form or format at all for the the PFD.
As for the reason(s) you're seeing it, it serves as sort of a heads-up for the FMEA process; the PFD is input to PFMEA. Note that KPCs and KCCs should also be addressed in the PFMEA.

 

[ramanbnv]

thanks.

Thanks. Both my customer and my auditor have recently insisted on these fields, and i was a bit put off since I was under the impression that it should be dealt with in PFMEA and Control Plan. So, can we just mention things like speed feed, etc without values and address the values in the control plan?

-Raman

 

[Jim Wynne]

Thanks. Both my customer and my auditor have recently insisted on these fields, and i was a bit put off since I was under the impression that it should be dealt with in PFMEA and Control Plan. So, can we just mention things like speed feed, etc without values and address the values in the control plan?

-Raman

There is no requirement to do anything except provide something that shows individual process steps in the order they're executed. No speeds and feeds, no machines, no nothing except process steps in order. Additional information may be added and may be prudent, depending on the circumstances. If your customer expects more than that, then you're beholden to the customer's requirements unless you can talk them out of them. As for the auditor, you should ask him/her to show you the requirements in the standard.
Here's what the AIAG PPAP manual (3rd Edition) says (emphasis added):

The supplier shall have a process flow diagram in supplier-specified format that clearly describes the production process steps and sequence, as appropriate and meets the specified customer needs, requirements and expectations..."

Note: If you have customer-specific requirements that call for detailed information on the PFD, and you don't have it, then the auditor was correct in pointing out the deficiency.