Process Control Plan Content: Relationship to PFMEA and Flow Diagram

[djmoran]

Process Control Plans

I'm working on control plans for our qs registration. I have a couple of questions -
1. Do Process Control Plans need to list all controls?
2. Does every step in the Process Flowchart need to show up on the Control Plan?
3. In relation to the PFMEA, if something with a high severity has a low RPN number because the occurence is low or the detection is high, does it need to be in the Control Plan?

Thanks for any help.
DJ

 

[Marc]

1. Do Process Control Plans need to list all controls?

Yes.

2. Does every step in the Process Flowchart need to show up on the Control Plan?

What specific step do you think might not be needed? A 'MOVE' step?

3. In relation to the PFMEA, if something with a high severity has a low RPN number because the occurence is low or the detection is high, does it need to be in the Control.

Is it a critical characteristic?

 

[DJ]

1. Thanks, it's a good thing we put them in already.

2. Yes, sort of - Transfer from Tank A to Tank B type stuff.

3. I think I'm confused on the meaning of the word 'critical'. Using the model in the APQP book, does it affect fit/function or does it have any safety/legal considerations - I can comfortably say no. Are there process controls that we have in place to address the high RPN's - yes.

Thanks for your help. This is the first time I've worked with Control Plans and sometimes I feel like I'm unneccesarily wrapping myself around an axle. I think you have an excellent forum here and find it a great resource.

 

[Marc]

2. Yes, sort of - Transfer from Tank A to Tank B type stuff.

Pipe or intermediate containers?

Typically the requirement is for 'critical characteristics' to be on the control plan. Critical characteristics are determined by your customer (if any) and by you. You might want to do a forum search for CRITICAL CHARACTERISTIC for some threads on these. Unfortunately there is no black and white here as to what you consider critical characteristics. Your PFMEA (and sometimes the DFMEA) should lead you to what characteristics are critical. And some are just 'common sense' -- Paint colour would be one in the paint industry as an obvious example.

Bottom line is if you are seriously confused about what may or may not be critical characteristics you may want to find a consultant in your industry and get him/her to come in for a day to discuss your thoughts. Or maybe there's someone here with industry experience who can help you out...

Any takers??