Engineering Changes--Class I vs. Class II Changes
Engineering Changes--Class I vs. Class II Changes
(OP)
Most companies employ change classes on their engineering change documents to indicate whether the changes are major (affecting form, fit, or function) or minor (eg, typos). My experience is that Class I indicates major changes and Class II, minor. However, I don't know of a reference that defines this common practice. I've checked MIL-STD-100 and ASME Y14.100, but I didn't see it defined in either. Is there such a reference?
Talk To Other Members
RE: Engineering Changes--Class I vs. Class II Changes
The thing is, if the modified part/assy is no longer fully interchangeable with older revisions then per Y14.100-2004 6.8 & D-13 it should normally be a new part number.
So in essence a class 1 change as you've defined it means new part number chased up through the assy levels until interchangeability is restored.
Class II is a true drawing revision.
Maybe look in ASME Y14.35M-1997 but I don't see it.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Engineering Changes--Class I vs. Class II Changes
"Class I changes affect an item's fit, form or function. These are changes that affect an item's specifications, weight, interchangeability, interfacing, reliability, safety, schedule, cost, etc. Class II changes are changes to correct documentation or changes to hardware not otherwise defined as a Class I change."
Interchangeability has its own set of requirements as well. Where I currently work our documentation is a plagiarized version of MIL-I-8500D "Interchangeability and Replaceability of Component Parts for Aerospace Vehicles"
Mike
RE: Engineering Changes--Class I vs. Class II Changes
Thanks for your inputs...very helpful Mike, you're reference led me to MIL-STD-480, Sections 5.1 and 5.2, which define Class I and Class II changes...just what I was looking for.
Thanks again!
Chip
RE: Engineering Changes--Class I vs. Class II Changes
Mike