Drawing Office Standards

[FIFTHTEXAS]

HI

does anyone know the correct procedure on drawing revisions, there seems to be some difference of opinion how cad drawings should be managed.

ie, preliminary, tender, construction, as fitted

is there a typical british standards document control procedure for management of drawings used in a drawing office. a procedure everyone can follow?

 

regards

 

fifthtexas

[merdrignac]

All I've ever known is to save each new revision with consecutive letters of the alphabet.

 

e.g. Drawing No. CW 890 001 Rev. A

 

On the drawing sheet should appear a revision box with the revision letter, the date of revision, and a brief description of the changes made.

 

e.g. _____________________________________

Rev Date

A: Street lighting added. 02/01/09

_____________________________________

 

Hope that helps.

[Lazer]

We use the same system as merdrignac, we also have production or development, controlled or reference only stamped on them.

 

You should base it around what works for you and the company.

[Strix]

I agree with Lazer - it varies according to what suits your business

 

'controlled issue' should always have a number which relates it back to a register which involves the confiscation of the old copy when a new one is issued

 

'as fitted' is usually termed 'as installed'

 

revision numbering is a point of debate as some companies start with an original drawing at 0 and the first revision to this is A, though some call the first issue A and the first revision is then B

 

if controlling paper copies of drawings is an issue through the design process, enable the plot stamp with the date and time, and stamp everything that comes off the plotter with 'info only'

[cadvision]

Hi all,

 

My first post for 2009. We use an alpha for all prelim revisions. concept, issued for review, issued for tender etc. Once is issued for construction or a master drawing in the database then it is numetric. I have some P&ID drawings at a clients faclity that are up to revision 30, so that out be a problem if you stayed just with alpha. There is the 1.1, 1.2 etc revision standard to, where you are making changed to current drawing of rev 1, each change until it is approved to replace the current rev 1 is 1.2, 1.2 ... then on approvel the next "master" rev is 2.

[merdrignac]

I think what we're all saying is find a system that suites your personal circumstances. The only must do is to save every revision separately and dated.

[dbroada]

The only must do is to save every revision separately and dated.

a pet hate of mine! If you link documents each time you change the file name you break all the links. I don't use XREFs but this is a good way to stop them working.

[Attila The Gel]

a pet hate of mine! If you link documents each time you change the file name you break all the links. I don't use XREFs but this is a good way to stop them working.

 

Maybe there is a way that auto cad ignores or understands certain codes in filenames? so when you add a rev or version after the filename. auto cad will still open linked files or the newest files.

We never use these so I don't know if this option does or does not exists?

But I certainly would like to know.

[Strix]

at the very least, you need a good archiving system

 

what MUST be done, is ensuring that you don't over-write previous revisions when you save the one you're working on

[dbroada]

at the very least, you need a good archiving system

 

what MUST be done, is ensuring that you don't over-write previous revisions when you save the one you're working on

pedant hat on for a while. What must be done is to determine whether the dwg file is a "master" in its own right or if it is just a tool for producing the MASTER file, paper or electronic.

 

We have a good archiving system but the wet signed bits of paper are the master documents. The dwg file is just a means to produce the piece of paper.

[Strix]

Nice hat DB

 

I've worked with both systems, but as the paper master system was nearly 20 years ago I was assuming it would have been superceded by something paperless by now

[dbroada]

I would have thought paper to be a bit older than that.

 

Housekeeping outside our department is pretty diabolical and 2 "master" documents, same issue, different content keep occurring, especially from within the "digital sigs" departments. We have yet to find a paperless system that is impossible to trick. Even our wet signed "RED ON MASTER" copies are being colour scanned so even the paper system is not foolproof but we produce far fewer duplicates than anyone else.

[Strix]

I meant the paper master system I worked with

 

strange thing is - their paperchase was pretty fantastic, and I encountered it as my first drawing office experience, so have been frustrated and disappointed with every other drawing office I've ever set foot in

 

mind you, they were doing nuclear power installations :wink:

 

They also had their own front-end database which acted as some sort of gate keeper for the drawing system - which was very effective at managing revisions

 

I had some interesting arguments with another control systems boss - but the upshot was that I decommissioned all of their stamps and ordered 'for information only', 'installation', and 'as installed' (or something along those lines anyway). All drawings were plotted with some rider in the title block to ring the office phone number printed on the drawing for the latest revision

 

basically I'd argued that as nothing that ever left our office had any form of control over it, NOTHING should ever be stamped 'controlled issue' - it just created a liability where it could easily be avoided

[merdrignac]

This all seems to me to be getting a bit involved. All I do is save each revision as a 'save as'.

 

So first save is for example:

 

CW067 001.dwg

 

subsequent saves:

 

CW067 001 rev A.dwg

CW067 001 rev B.dwg

 

Etc.

Each drawing is discreet, not linked, no loss of XREF connection.

 

All drawings Saved into relevantly named folders:

 

Planning

Engineering

External

Issued

 

Etc.

 

Never had any probs with this system, never (except once) lost a drawing, and always got back issues for reference.

 

Oh and by the way I always keep and automatic backup on an exterior hard drive. Never can be too careful.

[dbroada]

Each drawing is discreet, not linked, no loss of XREF connection.

That was my point. You may be working with discreet files. Othe companies use lots of linking and lots of XREF files. If I were to XREF CW067 001.dwg into my file and you now save it under a different name I would never be aware of the updates. Similarly if I have my table linked to a purchasing BOM which was moved I would loose my table.

 

Linking is becoming more prevalent as it means many departments can share common data. We are looking at a DBMS that will keep track of all our files (not just drawings). Continually renaming files could slow the DBMS as it needs to know what the latest revision is called. We often produce a drawing set that comprises in excess of 2000 files - I don't fancy updating that database!

[Kim Possible]

It sounds like we are all making this a little more complicated than those of us at a small company want to deal with. If you don't have the $ to implement a full drawing management database and you don't want to loose your xref links, here's what you need to do. When you open your drawing to begin your next revision, simply save it to an alternate folder within your project that holds all of your legacy revisions, (don't forget to give it your revision letter). You can do this through Windows explorer also, but I usually don't remember to do that. This way you have your saved revisions, and you haven't changed your master drawing. Voila! No xref errors and backups to boot!

[Teeds]

Let's confuse things further ...

 

Are you revising a drawing or a portion of a larger project?

 

In architecture and building engineering, I use revisions but we revise a project, not a sheet.

 

The architects might issue Rev A and the MEP engineers Rev B and the structural engineers Rev C and all three might have changes that are Rev D.

 

In that all files are archived, I copy the entire drawing file set to a new directory w/ the project suffix matching the revision number and that is the directory that gets the drawing changes. It always builds from the latest revision directory.

 

When I was the IT manager of a firm, I removed write permission from a directory once the drawings were sealed and issued. That stopped accidental changes. Now I just change the properties of the individual files.

[Jack_O'neill]

When I was the IT manager of a firm, I removed write permission from a directory once the drawings were sealed and issued. That stopped accidental changes. Now I just change the properties of the individual files.

 

That wouldn't prevent someone changing an x-ref that wasn't a part of that set would it? In other words, lets say you are drawing a building that has 1000 doorknobs called DK1 and you've x-ref'd DK1 instead of inserting it as a block. (I don't know why any one would do that, but this is just an example, so bear with me). DK1 is sitting on your server somewhere in a file of standard parts that you use a lot. Stuff like hinges and lock cylinders and windows, etc., you get the idea. Now lets say something about DK1 has changed. Doesn't keep you from using it, but the manufacturer is now putting a handle on one side instead of knobs on both sides. You update your DK1 file and continue on your way. But DK1 is x-ref'd into all these sealed files, what do you do then?

 

Granted the example given is a trivial detail and perhaps somewhat unrealistic, but it makes the point. If this were standard details of a truss or some other structural component who's actual construction or materials changed for one reason or another, anything it's x-ref'd to is going to get updated the next time those drawings are opened. The form, fit and function would remain unchanged, but the components and materials may have evolved. Doesn't matter (as long as it still works the same) to insert it in a future drawing, but if it something from the past that's gone to court, well, the devil is in the details in that case.

[Teeds]

Jack,

 

I understand what you are referring to, but remember that I would create a new copy of the entire directory for modification as part of the revision process.

 

I do not believe that there should be a standard symbol directory that is xrefed into a set of drawings for the specific reason you mention. Clearly, standard details are updated as manufacturers change their specifications and configurations. That being said, if the part was correct when the assembly was designed, then it remains correct until an individual part is reconfigured.

 

If the part was fabricated because of a certain configuration of the standard parts, it has to be revisited if a specific prefabricated part is redesigned.

 

We always copy any standard details into the active directory before we add them to any building.

 

Am I making sense, or am I running in circles?

[Jack_O'neill]

 

Am I making sense, or am I running in circles?

 

Understand completely. I agree with you, standard assemblies, details, parts and such as that should never be x-ref'd just for that reason. I did some outsource work for a company that would do it though. I really want to think that they are the only ones that are that ...uh....(don't want to use the word "stupid")....uh....misguided... but if one does it, someone else will. I always insert that sort of stuff then it doesn't matter what happens to the original, it's stays the same in that drawing.

 

I've gotten electronic drawings from architects that would have nested x'refs 3 or 4 deep. You never knew what was where, and they never managed to send them all for some reason. "A" would be a part that was xref'd to "B". "B" is an assembly that's xref'd to "C". "C" is a titleblock with a collection of xrefs that make an elevation, xref'd to "D" which is a collection of elevations like "C". They'd send "D", and maybe "B" if they thought of it, but no A or C so there would be big empty holes all through D where this stuff was supposed to be. Finally get it all sorted out and then they'd change something in "A" and just not bother to tell anyone.

 

I just wanted to point that out in case someone was contemplating doing it that way. Let's hope they don't!