Control Plan - Automotive - What To Put Where

[TownDawg]

What To Put Where: An Ongoing Discussion

The QE's here continue to discuss exactly WHAT information goes WHERE on a control plan. Any help that can be provided would be greatly appreciated. In a typical control plan, another QE has the following information in these three columns:

Product/Process Characteristics
======================
"Headrest Assemble", followed by "Prep Cover For Pour"

Product/Process/Specification/Tolerance
============================
Ensure cover alignment is straight, no sew defects present, finesse seams as needed.. (etc.)

Evaluation/Measurement Technique
=========================
Visual check by operator



I am of the opinion that there are no product characteristics for this step of the operation, but there are process characteristics: Alignment, Sewing Quality, and Armature Location.

Therefore, the Product/Process Characteristics become the CRITERIA for knowing we are successful, and the Product/Process/Specification/Tolerance becomes how the operator knows that those criteria are being met, and the Evaluation/Measurement Technique is how the operator determines that those criteria are being met.

I would love to be right on this, but both of us are really struggling with exactly WHAT information goes WHERE on a control plan. Again, any help that can be provided would be greatly appreciated.

 

[Jim Biz]

Opinion only

As far as my expierience has taken me
I have seen any number of "control plan" layouts -

Seems as if a "Control plan" - unlike an Fmea has very few rules to follow.

Many customers care less what "form" or detail is on our control plan (which in our case are really nothing more that re-titled inspection sheet layouts.

General Rules
Are inspection equiptment types identified on "the chosen control plan?
Does it identify critical characteristcs?
are frequencies of inspection detailed?

Whats possible>>>>>
Are customer SPECIFIED dimensions included?
Are customer EXPECTED (beyound print) conditions included?

One question tho ??? >>>how does one Measure and verify (show evidence of (in a repeatable manner) Visual inspection??

 

[Al Dyer]

Good post Jim,

Many times control plans are in the eye of the beholder and since they are living documents and the view can be revised.

One thing I would like to add is that my belief is that the FMEA must precede the control plan. (I know, Quality 101)

 

[Marc]

A look through http://Elsmar.com/APQP/ will show the normal sequence which is as Jim pointed out. And he's right on with control plan format. Ford uses what they call their 'Dynamic' Control plan. I have seen companies that use a form which has the control plan and the process flow diagram all in one. But - there ARE certain 'basic' columns which must exist. :thedeal:

 

[TownDawg]

Very enlightening. Like Jim, we have seen 'any number of "control plan" layouts.' Where we might disagree is in the statement that many customers care less what form or detail is in our control plan. In fact, some of our customers are very vocal about WHAT information goes WHERE.

You bring up many good points, Jim. Regarding visual inspection, how does one measure and verify?.. My take is that we use boundary samples and other product-related knowledge to determine whether the process is accomplishing it's intended result.

Without writing an epistle here, let me focus back on the original concept that us here are trying to reconcile. First: For each process step, as listed on the control plan, I stand by my original argument that a process characteristic always exists, but what about a product characteristic? I am of the opinion that there are no product characteristics for placing FIP headrest in a mold; only those related to the process – in that we have certain visual cues that tell the operator that the OIS (operator instruction sheet) is being carried out in a repeatable fashion.

I have seen control plans where the product characteristic is depicted as the ‘sub-component name’; i.e., headrest assembly. I struggle with this view of WHAT information goes WHERE. On the same control chart, the process characteristic is listed as ‘preparation’. Similar process steps (that follow this line of reasoning) would be listed as ‘clean’ or ‘demold’.

Al/Marc: If the FMEA is prepared in the Quality 101 order, then we know what those product/process characteristics are, because we have identified them during our investigation process. Since our goal is to ensure that those characteristics are being met, that information is transferred to the control plan. Further explanation of the how/when/where is described on the OIS.

Let me stop here, and see if what I am trying to say, hits home with anyone.

 

[TownDawg]

hMmmm.. apparently not, ehh?

 

[Al Dyer]

TD,

Sorry for the late response

I think? what you are saying is correct. In the following order:

Request For Quote
Contract Review
Contract Acceptance
Characteristic Matrix (What)
Process Flow (How)
FMEA (What can go wrong)
Control Plan (How do we control what can go wrong)
PPAP
PPAP Approval
Continuous Improvement through FMEA RPN's

Revise FMEA and Control Plan as needed.


Short response, anybody else??

 

[TownDawg]

Thanks, Al. I had about decided that 'views and lurkers' was the only response I was going to see.



1) (True/False) A process characteristic always exists at each process step.

2) ... but what about a product characteristic?

3) ... control plans where the product characteristic is depicted as the ‘sub-component name’ ... struggle with this view of WHAT information goes WHERE.

=======================================
Those three specific questions I am looking for feedback.

 

[gpainter]

Depending on your specific industry your plan may be different. This is what is on our control plan, as is more than likely is what is on most control plans:

• Parameter - what you look at
• Specifications - measurements
• Tolerances - measurement + or -
• Method - how and or what measuring
• Instrument used - may reference WIs
• Frequency - how often done
• Owner - who is responsible to take the measurements
• Data location - where info is store
• Reaction plan - what to do if out of tolerence

We also have signed and dated approvals by engineering/quality and production.

 

[Jim Biz]

1) (True/False) A process characteristic always exists at each process step.

2) ... but what about a product characteristic?

3) ... control plans where the product characteristic is depicted as the ‘sub-component name’ ... struggle with this view of WHAT information goes WHERE.

1) True in normal situations
2) tolerances / descriptions/ methods
3) Wondering why a characteristic WOULD/SHOULD be depicted as a sub-component name??

(If I wanted an automobile to achieve say 55-70 mph at 3000 rpm ...... doubtful I would/should describe the characteristic as simply "engine & drivetrain" on a control plan??)