Revision History Block 1

[LONDONDERRY]

Our Configuration engineer and I have a slight debate on if a Revision History Block is allowed beyond Sheet 1 of a multiple page detail drawing. I looked it up and its says it permissible on multiple sheet, but the description has to say "SEE SHEET 1" the CE says its not allowed ever. can someone weigh in on this debate?

 

[MikeHalloran]

Related subjects have been done to death. Search all the forums, including Engineering Configuration Management.

Is your CE perhaps quoting some other company's drafting standards manual? It's the sort of thing that should be in /your/ company's manual, so you may need to work together to produce one, or settle the question in one that exists.

The box for 'see sheet 1 for revisions' would/could have been part of the format in olden days. You could make it small so it didn't take up much space. Failing that, and probably anyway, words to that effect should be in the standard package that you send out to vendors with every rfq and every order, and/or in your standard contract.


Mike Halloran
Pembroke Pines, FL, USA

 

[LONDONDERRY]

"Is your CE perhaps quoting some other company's drafting standards manual"
Exactly.. CE alway tell me that "well at LockHeed, we use to do it this way"

 

[MikeHalloran]

There's an old rule in science about experiments and record keeping:

"If you didn't write it down, it didn't happen."


I will postulate a counter- corollary for companies that have grown large enough to need people like a Configuration Engineer:

"If it ain't written down, and signed off by the usual suspects, it ain't gonna happen."


Perhaps, in as friendly a way as possible, you might point out to your CE that he doesn't work at Lockheed anymore.

If, as I suspect from his job title, he was hired in part to bring some semblance of organization to your particular circus, he's not getting it done.

GE used to license its drafting standards manual, which actually filled a tall set of bookshelves, for an obscene amount of money.
Perhaps Lockheed does the same thing.

You can have any damn drawing/design standard, however illogical, strange or bizarre you want it, but before you can enforce it, you have to write it down, and get it approved by The Big Guy.

Until that happens, everyone is free to do things their own way, or however they remember The Big Guy told them to do them. ... and they're also free to ignore both you and the CE.


p.s.
Also tell the CE that I have personally seen people get fired on the spot for saying stuff like "We did it differently at XYZCo" one too many times.
Food for thought.


Mike Halloran
Pembroke Pines, FL, USA

 

[LONDONDERRY]

Thanks Mike-
Words of wisdom.
As you can probably guess from my past posting most of my dilemma has been with either SCM or Configuration Management. All of the CM/CE came from the Raytheon/Lockheed companies. Our company of 1800 (which is a s/w Googlish company) has one I repeat one Mechanical Engineer (me) that support/designs our products even though they are domestically out sourcing more and more these days. Size is no excuse for bad drafting practices, which I take pride in, however we have zero drafting procedures', so I fall back on ANSI/ASME standards. However, I consistently butt heads with CE as they want to take what they used at Lockheed and apply it here. For example we have an ECO process so crushing to use because CE's set it up as a high volume defense manufacturing base, even though we lack staffing to properly process it.. So releasing a simple product through our ECO process will take 3 months.

 

[MikeHalloran]

Maybe the solution is as simple as buying a few copies of a drafting standards manual you like, and getting it blessed at a higher pay grade.



Mike Halloran
Pembroke Pines, FL, USA

 

[tbuelna]

The only reason to include a revision history block in the upper RH corner of each drawing sheet after the first sheet is when the sheets are not maintained at the same revision level, which is not common. There is usually a revision letter shown in the title block of each sheet, which is all you really need.

However, there is nothing in any CM procedure I have seen that prohibits using a revision history block on each drawing sheet with the notation "see sheet 1" described. This is commonly done, and the reason for using the notation "see sheet 1" is to minimize the potential for errors from entering the same information on several sheets.

 

[CheckerHater]

To the best of my recollection, the standard says something like:

Revisions may be by:
[ul]
[li]‰ Drawing Level Method[/li]
[li]‰ Sheet Level Method; or by[/li]
[li]‰ All Sheets Same Revision Level Method.[/li]
[/ul]
As I don't have access to the book right now, I hope somebody in possession of ASME Y14.35 may confirm or disprove.

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[patdh1028]

Looking through Y14.35, it definitely does not exclude the use of revision blocks on each sheet. For the "All Sheets the Same Revision Level" method, section 7.3.2 says "Additional Revision History blocks may be added when required in accordance with Y14.1(M)" and "When Revision History blocks are used on continuation sheets, all sheets shall be updated whether there is any other specific change on a specific sheet."

14.1M doesn't have any real limitations on which sheets can/cannot have rev history blocks. I think as far as the ASME standards go you're correct that there can be RH blocks on all sheets even if all sheets are the same rev level. I didn't see anything about "See sheet 1" required.

Fun fact that Y14.35 section 7.4 claims "Revision Status of Sheets block is required on multisheet drawings." I've never even seen one of those blocks before - who knew?

 

[LONDONDERRY]

All-
Thank you for the great information. What I'm up against is a Configuration Manager and his minion Configuration Engineer both whom worked at Lockheed and want to institute their former company's drafting procedure here, even though nothing is in writing. I believe the best way to deal with petty issues as such is to have CM and CE shown me the ASME standard if something is n question.

 

[TheTick]

What I don't like about redundant rev blocks (and redundant BOMs) is that it caters to blockheads that don't understand what a controlled document is. This is the type of bad habit perpetuated for the benefit of those too lazy or stupid to understand that everything does indeed have its place.

How many redundant BOMs and rev blocks do you want to control and check? Are you going to check them all? No? Because they're "automatically updated"? Good luck with that!

 

[tbuelna]

"Fun fact that Y14.35 section 7.4 claims "Revision Status of Sheets block is required on multisheet drawings." I've never even seen one of those blocks before - who knew?"

I think this is a list next to the title block on the first sheet that shows the current rev level of each sheet of the drawing. This was a common practice back when everyone worked from hard copies of a drawing. And it helped to ensure the drawing prints being used were the most current version, since the first sheet was always updated at any revision.

 

[TLHS]

From a more practical standpoint, if you're the only Mechanical Engineer why does anyone else care how you do it as long as you're consistent and clear in the way that it's done?

 

[LONDONDERRY]

THLS-
Thats what I'm up in arms about we have 1800 employees and one ME (me) and some of the folks in SCM, CM, etc come from Lockheed, Raytheon and want to institute all the manufacutring procedures within a software company that is outsource most of its mechanical engineering to a contract manufacture. You should see how bad our ECO process is, they've created a process that is so crushing to use that from the time I submitt an ECO to the time of release is weeks and weeks.. becasue half of the approvers never seen or heard of an ECO..reasons like this I'm bailing out

 

[akitasumo]

ASME Y14.35M, sections 7.3 and 7.4, states for multi-sheet drawings the use of a revision status of sheets block is required or a statement such as "all sheets are the same revision level". If you change all sheets are the same revision level method and you have revision history blocks on the successive sheets, the revision history block gets updated even if that sheet did not change. Since most drawings are CAD driven now, all sheets of the drawing are in the same file, I would recommend using the same revision level for all sheets and removing the revision level history block from all successive sheets.