Revision description on drawings.

[cathat]

This may sound insignificant to some, but today its a pain in my side.
Topic of the day is revisions on drawings. In the past insignificant changes to drawings may not have been included in the revision description, for example: move view from right side of dwg to left side of dwg, change 2x to 2X... These types of changes that we find that have no impact on the part. Today I have new quality personnel requesting we make mention to anything that may move or change on the print... anything in red gets mentioned whether or not insignificant. I disagree in part but I have no standard to stand on so I may have to concede. I want to fight this but cannot find anything to prove my point anywhere in the ASME standards.

Any suggestions? I can always make a blanket statement of "UPDATE TO CURRENT STANDARDS", but that is so vague...

 

[ewh]

... for example: move view from right side of dwg to left side of dwg

Changes such as this should be noted, as there may be Quality documentation refering to this view. As for recording a change of "2x" to "2X", I think that is getting a bit pendantic but is technially correct. ASME Y14.35M-1997 ¶ 4 "...Any change to a drawing after release... requires the revision level to be advanced and shall be recorded in the Revision History block" or other revision authorization document (¶ 6.1.3(d)).

“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV

 

[ctopher]

A few months ago we changed our system to say "Released per ECN12345" or "Revised per ECN12345" in the rev block.
You have to look at the ECN online to see what the change was.
This is less labor intensive and shortens the rev block, and less errors.

Chris, CSWA
SolidWorks 13
ctopher's home
SolidWorks Legion

 

[pmarc]

I recommend Y14.35M-1997, "Revision of Engineering Drawings and Associated Documents".

Paragraph 5.1(e) says:
"When minor changes not affecting form, fit, or function, such as correction of misspelled words or addition of reference dimensions, are required on the drawing, the changes should be incorporated at the same time as other revision authorization documents."

 

[cathat]

I appreciate the replies,

Cathy

 

[drawoh]

cathat,

Who needs to know what was changed on your drawings, and how much work should you do to keep them happy?

We do the UPDATED AS PER ECO... bit. This is fine in-house, where we have access to the ECO. It is of no use at our sub-contract fabricators, who have no access to the ECOs.

--
JHG

 

[KENAT]

We do updated per ECO and just a one or 2 line description of changes we really want to flag to the drawing user.

(However, our ECO's don't give as much detail on drawing change as we used to give in aerospace/defense.)

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[3DDave]

In the past there was only one original of a drawing and copies could not be made of any particular version except the latest.

I've seen some drawings of simple parts where you could re-draw the original release from the notes in the gigantic revision blocks. This concept does not scale well.

Nowadays, an infinite number of copies can be made of any electronic version of a drawing. Under electronic distribution and information control systems it's a waste of time to include information about what changed on a drawing. There are numerous ways to compare any versions to see exactly what changed. If you want to take pity on your downstream users, then create ECOs that have sheet and zones identified with lumpy balloons and Was, Now all over it. Electronic comparison is still better because it will find items that get changed accidentally.** Usually things like a leader to a balloon or note is lost because the item it pointed to is gone or replaced, even though the balloon or note still matter.

I find it's more important to find a place and way to record Why it changed.

**True story, back in the day, I see a drawing incorporation that has each view appear covered in scribbles; reason for change? Clarify drawing. How it happened is the guy got over excited about getting the incorporation approved, so he zoomed in on the release block, filled it in, and set the software to create the plot file. He didn't notice the views set to default to the user environment (wireframe and tangency lines) instead of purposely being set to hidden-line removed/no-tangency. Since the checker was already done with it, and who could mess up a single line in the release block, there was no check before attaching the file to the PDM record and releasing it.

 

[MikeHalloran]

I hate to see only 'SEE ECN XXXX' and so forth.

I'd much rather see something like "ECN XXXX ; HORN WENT BEEP", with the ECN itself carrying as much detail as the most pedantic person in the organization wants to see, and the line in the revision block at least describing what happened.


Worst case I've seen so far is 'SEE ECN XXX' where the ECN itself ran to 140 pages. We had been accused of issuing too many ECNs, and that was the response; one ECN to cover changes to half the product. Let's save that for another discussion.








Mike Halloran
Pembroke Pines, FL, USA

 

[3DDave]

I had a boss that put the ECN log book on his desk. He had taken it away from Document control because "Engineers are just making changes." In less than a week he'd double-booked a bunch of ECNs. Document control got the book back and I guess he found out that Engineers were making changes for something other than the joy of it. He still asked us to stop it, but he was no longer as strident about it.

 

[lwealing]

I recommend Y14.35M-1997, "Revision of Engineering Drawings and Associated Documents".

Paragraph 5.1(e) says:
"When minor changes not affecting form, fit, or function, such as correction of misspelled words or addition of reference dimensions, are required on the drawing, the changes should be incorporated at the same time as other revision authorization documents."

I believe the intent of this paragraph in the standard is to suggest that ECNs should normally not be issued specifically for the intent to correct misspelled words and the like. Rather, these changes should wait and be included on an ECN that has higher ROI in which such changes can be incorporated easily with low cost.

 

[looslib]

We use 'Released per CR####' in the drawing revison block.

One former company used revisions like A1, A2, A3, etc. where the # was an element of what was done in Rev A. The description field would say: Sht1, E7 - R.375 was R.250. and each change was documented.



"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli

 

[cjccmc]

I was always peeved by the fastidious checkers who wanted to see every little nit described in detail. Reason being that I can produce a whole new part and not explain why I did any of it but change something and the world needs to be able to fathom it all in unmistakable detail. My favorite description from old ink dwg days was "revised and redrawn".

 

[drawoh]

... My favorite description from old ink dwg days was "revised and redrawn".

If I am your fabricator, this tells me that you have changed everything, and that I must completely re-write my CNC code and/or completely re-build any tooling I have. If this is what you should be telling me, fine. If your revision blocks tells you moved two holes by .25", I can update my CNC and modify my tools, and charge you less.

Many, many years ago, I took over a drawing package in which people had been doing revisions without any documentation whatsoever. I started at revision[ ]5, and I described it as "REVIEWED AND REVISED".

--
JHG

 

[ingallspw]

I agree with MikeHalloran. I would also rather see a small description of the change. Even if it's only the most recent change...

 

[looslib]

One place I worked used what they called Unincorporated ECNs. The paper work for the ECN was done but the drawing had not been updated to the latest ECN. Working on a project and new revisions to drawings were coming at manufacturing fast and impacting the build schedule. Only revisions are tracked from a cost standpoint. Directive from the division president comes down: No more ECNs on this project unless they have the program director's approval. The revisions almost immediately stopped....however the unincorporated ECNs, which were limited to 5 before being incorporated, had that limit raised to 25 for this project and they came as fast as the revisions had before. BUT, the program complied with the presidents's directive. Unfortunately it made even more work for manufacturing becasue we used a different CAD/CAM system and now we had to model the changes to produce NC tapes instead of getting the latest IGES model from engineering.


"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli