Control Plan Flow compared to Process Flow Diagram

Is it a requirement that the Control Plan follows the exacts steps of the Process Flow Diagram? I mean, if all the information is present on the Control Plan (compared with the PFMEA and Process Flow Diagram) does the Control Plan have to follow the exact same flow? We have Control Plans that contain all the steps and information but do not flow exactly the same as the Process. I havent found anything in the APQP manual or TS where it says the Control Plan has to follow the exact steps of the Process Flow Diagram. I understand it is easier to follow if it does but is it a requirement?

I have always worked that way.
- setting up a numbered process flow
- performing FMEA - same numbers used
- setting up control plan - same numbers used

I don't know if it is a requirement but it is useful as reference through the 3 documents.

best regards,

Antoine

Rowdy said:

Is it a requirement that the Control Plan follows the exacts steps of the Process Flow Diagram? I mean, if all the information is present on the Control Plan (compared with the PFMEA and Process Flow Diagram) does the Control Plan have to follow the exact same flow? We have Control Plans that contain all the steps and information but do not flow exactly the same as the Process. I havent found anything in the APQP manual or TS where it says the Control Plan has to follow the exact steps of the Process Flow Diagram. I understand it is easier to follow if it does but is it a requirement?

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I don't have my PPAP manual handy, but it says something to the effect that the PFD must show the sequence of operations. If your PFD is different in this regard from your control plan, one of them is wrong, so I can't imagine why their being different would be considered OK, regardless of standard requirements.

The need for Process Flow steps to numerically match the FMEA and Control Plans is implied in the AIAG checklists:

A-4 Product/Process Quality Checklist 17. "Is each operation provided with process instructions that are keyed to the control plan?"

A-6 Process Flow Chart Checklist 3. "Is the flow chart keyed to product and process checks in the control plan?"

Some Automotive OEM's directly require in their documents and quality system checklists that the core documents must numerically align by step and derived from the interpretation of the word 'keyed' as the easiest key is a numeric one.

Consequently, most core document software requires that all process steps numerically align (reference MPACT, Customer Driven Systems, XFMEA, etc.).

You are correct that there is not an explicit requirement in the AIAG PPAP manual that requires line item numeric alignment and the other AIAG manuals are considered 'recommended practice'.

Had a customer audit for this exact thing last week. I found it odd that he didn't seem to care what our router said, even though that is the driving force that controls the order of operations on the manufacturing floor. He was happy because the control plan and process flow matched. For many customers APQP/PPAP is an exercise in dotting Is and crossing Ts, not value added improvement.

The test for many SQE's auditing a supplier process is "can I walk the process using the documents provided? - Flow Diagram, PFMEA, Control Plan?"

Some OEM's ask "Are the documents linked (Key'd) ?"

These are supeanable documents in US courts that can be used to determine DUE CARE and assign liability in the event of a catastrophic failure. REF: Ford/Firestone issue some years ago.

Much of the information and methodologies has changed over the years some for the good and some due to lack of understanding not so good.

Most of the OEM's are delighted to see...

Every Step of the Process (anywhere the material/product goes)
Every Step of the process that is also an operation (anything that changes the configuration of the material/product).

And that the Flow, FMEA, Control Plan are linked.

The reason that they are happy to see that is... Once they sign off on the PPAP they are assuming a certain amount of liability and they feel more comfortable that you really have an understanding of your process.

Typically you might see...

Step 1 Rec Raw Material
Step 2 Move Material
Step 3 Store Material
Step 4 Move Material
Step 5 (Operation 10) Mold Material
Step 6 Move Material
and so on.

The PFMEA would capture the same Steps and Operations.

The Control Plan in many cases would be the same sequences but may not cover everything and may look more like...

Step 1 Rec Raw Material
Step 5 (Operation 10) Mold Raw Material
And so on.

Very much like another poster indicated.

If your material routing is different than your Quality Documents you may have an error in one or the other - I would imagine that someone may have asked for the routing at some point in time, however I suspect that this is rare.

If your documents do not match what is on the floor you are increasing your companies potential liability, which many agree is a primary purpose.

TR