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Managing Your CAD Data

By Eric P. Leitner, CSP, CSM, CIM, C.Tech., OAAAS, AMIEEE

"I need a set of prints for that project we bid last month by noon" came the voice from deep inside the manager's office.

"Why is he always in such a hurry?" John thought to himself. "Now, let's see. Which one of these files has the most current drawings. I know it's in here somewhere..."

Two hours later John was still sorting through the files, trying to figure out which ones were current and which ones were nothing more than "what-ifs." He couldn't decide between two or more versions on a couple of pages, and one of the pages seemed to be missing entirely!

These types of scenarios are all too frequent in many of today's modern design offices. Trying to sort out which file is current and which one can be safely deleted is no simple matter. The proliferation of office networks and the sharing of CAD design tasks among several employees only serve to compound the challenges.

Ultimately, a little planning at the start of a project can save immeasurable grief further down the line. Usually, by the time there is some pain being felt, the act of cleaning up the files is far more time consuming than if the planning had been put in place at the beginning.

Here are some common CAD file issues, and some helpful suggestions on how to avoid at least some of the more common traps.

Last Save Wins:

In some offices, CAD users are not all that disturbed by seeing messages such as "File already in use. Open as Read-Only?" The problem with ignoring this message is that these users sometimes make changes to the re-opened file, and then try to save it back. If more than one person saves the file back to the network with the same name, the last person to save "wins," or at least they overwrite everybody else's work (if you can consider that a win).

Date or Revision in the Filename:

Another very common way that files spin off multiple children is when dates or revision numbers are used as a part of the filename, such as in My_Drawing_Feb5. or My_Drawing-03. Revisions still split off from each other, creating multiple copies of part or assembly drawings.

Proper tracking of changes through ECOs (Engineering Change Orders) or other documentation would save countless headaches. Also, noting the changes to a drawing using revision clouds and a revision table would also go a long way to avoiding those last minute aggravations.

Versioning and Revision Tracking Software:

Some software manufacturers also offer version and revision tracking software that plug right into the CAD interface. The process here is that files need to be checked out by a user, just as in a library, before any changes can be made to them. When the file is checked back in, the software tracks who made which changes to the file and when. The same filename is kept, and the version number is incremented.

At any time, a user can ask to see the file as it was at any point in its history. Project managers can also see who currently has possession of any file, and get a good idea of what stage a drawing set is at by looking over the conditions of the files and can even change the status of a number of files at the same time.

Of course, all of this comes at a price. Since every previous version of a drawing is stored on the network, extra drive space may be required and completed projects should by properly archived and pulled out of the system.

Cross-Referencing:

Having drawings reference one another is one of the most powerful and most underutilised options in most CAD packages. Cross referencing, sometimes called external referencing, allows one CAD user to bring somebody else's drawing in to their own work and add to it. The power comes in updating any new changes made. With referenced drawings, all of the drawings down the line are automatically updated.

Avoidance or banning of referencing in an office is typically a result of not understanding the structure of cross referencing. Once bitten; twice shy. Anytime referenced files are moved or renamed, problems can occur. Still, the benefits far outweigh the drawbacks, and it is certainly worth learning how to use cross-references.

Project and Folder Structure:

The creation of folder structures, especially on a network, is another one of those topics that often doesn't get enough attention until problems have started to surface. Have a standard folder structure and naming convention, and stick to it.

CAD projects can now be organized across multiple sheets, even if these are in separate files. Titleblocks, callouts and page numbers can now also automatically adjust. This is especially useful in larger sized projects, where changes frequently occur.

The big pay-off here is that project files, if properly set up, will know what drawings are associated with a job, and can print an entire drawing sheet set at the click of just a few buttons.

Archiving Completed Projects:

Don't forget to clean up after yourselves— and do it smartly. If you are running version tracking software, use the backup utilities included in the package.

Make sure that any project removed is complete in every way. You might not think of burning a copy of your fonts, pen settings and lineweights now, but you may have to work with a drawing set many years from now? The information on the backup should be everything required to revive the project, whether in six months or in six years.

All offices are different, and that means that each may have a unique solution to its file management issues, and consultants can help. Creating templates, structure and a file library can be a one-time thing, and the time required to learn these systems may not be worth the effort. Most local CAD resellers either have technicians in-house or know of reputable consultants that can help take the pain out of drawing management.

Three months later...

"John, stop what your doing right now. I've just been called to an important meeting regarding that downtown project, and I need a complete set of drawings before you go home tonight, no matter how long it takes you."

"Hmm," thought John to himself, "some things will never change around here." Luckily for him, some other things had changed.

"Sure, boss," he replied with a smile. "I'll just set the job to print before I go for break. You'll have your drawings by the time I get back."

Sometimes change — the right change — is the best thing in the world.

Eric P. Leitner is a Certified Technician (C.Tech.) in the disciplines of Building/Building Design, Computing and Electronics with OACETT, as well as an associate member of OAAAS. He also holds CSP, CSM, CIM and AMIEEE professional designations. Eric owns and operates ÆSIR International Ltd., an Ottawa-based CADD consulting firm specializing in CAD data management, software training and 3D modeling.