Statistical Software Calibration using Ford's "Sample Calibration File"

First post - please be gentle.

I work for a major UK OEM who runs Ford based APQP/PPAP systems. We use a PPAP check list based on a Ford document. One of the questions under 'Initial Process studies' section reads:

"Was a statistical software calibration, using the Sample Calibration File conducted?"

I've asked around (my organisation) within STA and Six Sigma communities to a senior level. Nobody is able to provide me with a "sample calibration file". I've looked through the AIAG SPC (2nd Ed) & PPAP (4th Ed) manuals and can't find any referance to statistical software calibration. Not even Google can help. My Manager suggested I try asking on Elsmar Cove.

Can anybody shed light on this? Idealy I'm looking for a copy of a/the "sample calibration file" and instructions how to use it to perform a statistical software calibration.

I'm asuming it's just a data set, with verified statistical properties, which can be used to check the output of suppliers spc spreadsheets.

Any help greatfully recieved.

Thanks,

Andy Skelton

Re: statistical software calibration

Welcome:
Do you perform calibration? or do you just have equipment that require calibration?

Re: statistical software calibration

Ford produced a dataset some time ago that's intended to be used in "calibrating" MSA software. "Calibration" is simply the act of comparing something to a standard. Have a look at the attachment in the first post in this thread. Although it dates from 2006, I don't think mathematics has changed since then. There are by now many thousands of home-brewed spreadsheets and commercial software packages for doing MSA calculations; doing the "calibration" is a safeguard against spurious results.

The idea is to plug the numbers from the dataset into your own MSA program and see if you get the same results.

Re: statistical software calibration

That sounds like the kind of thing I need, but for Cap studies. I found an example MSA data set in the back of the SPC manual!

Re: statistical software calibration

AIAG has a sample set, however you will see in my blog that it is likely incorrect. Capability Calculations: Are AIAG SPC Appendix F Conclusions Wrong?

Re: statistical software calibration

bobdoering said:

AIAG has a sample set, however you will see in my blog that it is likely incorrect.

Click to expand...

I've read the opening paragraphs to your post and I appear to have a problem with my AIAG manual. I'm looking at a 1992 print of the 2nd edition of the AIAG SPC manual. My Appendix F is a lookup table of Pz from z, and not a sample data set. It's 1 printed page of data, with no figures. Am I looking at an out of date edition?

Thanks

Re: statistical software calibration

BRILLIANT - that's it!

Thank you so much, I never thought I'd get to it so quickly

Re: statistical software calibration

Jim Wynne said:

Ford produced a dataset some time ago that's intended to be used in "calibrating" MSA software. "Calibration" is simply the act of comparing something to a standard. Have a look at the attachment in the first post in this thread.

Click to expand...

This is the post I'm refering to in my last post of thanks

Re: statistical software calibration

Andy S said:

I've read the opening paragraphs to your post and I appear to have a problem with my AIAG manual. I'm looking at a 1992 print of the 2nd edition of the AIAG SPC manual. My Appendix F is a lookup table of Pz from z, and not a sample data set. It's 1 printed page of data, with no figures. Am I looking at an out of date edition?

Thanks

Click to expand...

You have the second printing of the first edition (1992), the second edition is July 2005.