Hi, All
The company I'm working for is currently seeking NADCAP re-accredition. This year SPC deployment is expected to be auditted and some core requirements in AC7108 Appen A are mandatory, such as FMEA, control plan, Pareto analysis,etc. They are not too bad, except in NADCAP checklist no detailed instructions are ever given (what set of columns are required, so on so forth, I guess the auditor will have the final say). However, there is one core requirement I really have trouble with and hope someone can help out:
A4. Process Control
A4.1 Are there documented criteria for determining that a process or process variable is in control?
Mind, control charts are not required at this stage, and we didn't implement one either, (we have trouble to use variable control charts, attribute control charts may be the way to go in the future). From what I understand is you have to have control charts, detect the patterns, compare these patterns to a set of criteria to decide whether the process is in control or not - so my question is what kind of criteria NADCAP checklist is talking about?
I will really appreciate your help.
:thanx:

Are there documented criteria for determining that a process or process variable is in control?

Dear Ann,
I think they are asking for set parameters. Do you have process setting charts? - i.e Have you validated your process and came to a conclusion, in which parameters your process is giving desired outputs.

I am not familiar with the certification you are talking about. May others also give their views. What kind of process you are working with? Anything specific to manufacturing?
Sowmya

I am also not familiar with the acreditation you are looking for, but...

Why do you said "control charts are not required at this stage, and we didn't implement one either, (we have trouble to use variable control charts, attribute control charts may be the way to go in the future). "?

* What kind of troubles do you have?
* Why "control charts are not required at this stage"?, if so the A4 and A4.1 does not apply....?
:confused:

If I read Are there documented criteria for determining that a process or process variable is in control?. It came into my mind, wich criteria do you use on control charts to determine the state of the variable (in control or not), like the rules of GM for control charts (ie. 3 points outside of control limits or the inexistence of out of control rules in a month, to say something). Take it as an Idea, but how could you have rules for control charts and don't chart any?, thats the question.

A4.1 Are there documented criteria for determining that a process or process variable is in control?

The criteria I use is documented at http://www.hanford.gov/safety/vpp/spc.htm.

There are several variations out there. For example, Dr. Wheeler espouses 8 in a row the same side of the average is a signal, while most others use 7. The key is to pick one set of criteria, document it, and stick to it. You are welcome to make use of our criteria, if you choose.

Dear Ann,
I think they are asking for set parameters. Do you have process setting charts? - i.e Have you validated your process and came to a conclusion, in which parameters your process is giving desired outputs.

I am not familiar with the certification you are talking about. May others also give their views. What kind of process you are working with? Anything specific to manufacturing?
Sowmya
Dear Sowmya, we are a plating shop. We currently have documents for all parameters of every process we do. And they are in chart fomat. If that's what they asked, then I have it. But I doubt that's it.

Dear Darius
* What kind of troubles do you have?
* Why "control charts are not required at this stage"?, if so the A4 and A4.1 does not apply....?
I really have trouble of constructing variable control charts for some quality characteristics such as plating dimensions. The reason being that we have many different parts coming to us, but in small quantities, taking long time to finish (tooling up, set vessels, plating long hours, etc.) - we don't have the volume - it almost seems we always working on something different (maybe not that bad, but for a control chart...). I believe there must be ways of dealing with this kind of situation. If you can introduce some literatures/ papers specific for this sort of production, I will really appreciate it.
NADCAP has a set of core requirements in the checklist format, at this stage, control charts are not among the core requirements, so you don't have to have them, you may never have to have them, but the documenting of criteria is, you must have it (as I cited in the previous post) - it sounds so odd - that's why I'm confused. Well, not sure what criteria they have in mind. Check their site, can't find anything. :bonk:

Dear Steve,
thank you so much for the document. If I can not figure out precisely what they (NADCAP) have in mind, I will just use the point pattern criteria, saying it is the criteria we are going to use in the future. I have some reference books with lists, but I like the way you present it, clearer, - so thanks a lot.

NADCAP is an accreditation for chemical processors who are in the Aerospace/ Defense Contractor sector, we have it for two years and this time around, SPC is mandatory. But there seems very little guidelines aside from the checklist - more like automotive standards without any referencing manuals. Plus, we are a small company, and I'm a research chemist, helping QA out, so everything is a bit hairy. So really thanks for all the helps you guys provided! :thanks:

Ann you said:

The reason being that we have many different parts coming to us, but in small quantities, taking long time to finish (tooling up, set vessels, plating long hours, etc.) - we don't have the volume

An excellent book is Innovative Control Charting, Practical SPC Solutions for Today's Manufacturing Environment by Stephen A. Wise and Douglas C. Fair, ASQ Press (I expected more from this book but it's excellent).

This kind of Charts are called Short Run. or ""Z charts", I added an article about them.

Alltho, if is a chemical process maybe needed some autocorrelation factors added to the calculus (too much relation between each sample), but it's an start point.

And about documentation, don't put a rope in your neck (don't put too many rules, is what you expect of an stable process). :lmao:

Does anyone have written procedures or criteria for incoming Printed Circuit Boards?
SASS

Ann,
I have been through 2 AC7108 audits in the past 12 months. It was quite a learning curve. The company that hired me was in trouble and lost the accredidation due to a lack of compliance with Appendix A. Compliance to appendix a is required after 2 years of AC7108 certification. The most difficult part of meeting appendix A is determining the difference between the Project Specific requirements, and the system specific requirements. I will tell you, I approached it as a Six Sigma Project (which is what they are looking for) and did not have any issues. One thing to keep in mind is that some of the core requirements will change yearly. As they are specific to the Annual Project that is due. For example the FMEA/ Control Plan will be project specific, but all of section A will be System specific. I have one procedure that covers all of the System Specific requirements, it is included in my manual, and controlled as part of my system. For the annual project, I put together a powerpoint presentation and had 1 slide for every part of Appendix A. Critical Items to Remember:
1. Milestone (or Gantt Chart) Ensure this is up to date, that you comply with your targets, and that you show management has reviewed and commented on the chart.
2. Defect Pareto. Ensure your defect pareto breaks down your Company Wide PROCESS issues. (The term process can apply to Mfg. AND system processes). Ensure Management has reviewed this and determined the area that needs addressing from the project.
3. Develop another pareto/chart for your PROJECT, based on mangements determination, and begin the project.

Keep in mind the standard is very generic and intended to be used across the entire QMS, and MFG processes. I would suggest choosing something you already have data collection capabilities in the facility on, that you can tie to your top level defect pareto.

In response to your question about process control, A4.1. This requirement is in regards to your project, not what you currently have in-place in your facility.

One thing I suggest, do all you can to pass this area during your audit. If this section is identfied as an NCR, the Staff Engineering Review can be much more difficult than an auditors review.

If you would like further information I am more than happy to assist in any way.

Eric

Dear ealtomore,
Sorry didn't reply on time, and really thanks for the input. I have heard many friends in the business said the same thing, that App. A is the killer. I really am nervous about it. Here are the steps I chose to follow, hopefully it will tie us over:
1. Do data collections on all defects based on processes (as in traditional MFG process)
2. Pareto analysis
3. Identify target process - choose it as our project
4. FMEA and control plan on this process
5. Keep on going Pareto analysis for this project - review, re-assess
Will this scheme work for now?
After reading your post, I think I have to work on Milestone more, get it to be more systematic and specific. I can see now how A4.1 ties into the project
I sort of understand the project specific approach, but when you say system specific requirements, you are referring to all the SPC tools that will be used and when and where (QMS and MFG systems) they should be used - my understanding, is it right?
Thanks for the help again! I'm so glad somebody has success story to tell - I heard too many horror stories so far and am truly depressed :frust:

Dear Darius, thanks for the introduction of the book and the article, I will order the book and read through to get some ideas.