BAD CAD - finding the flaws in Files
Take
the time to make a progressive investigation. Take
notes. Be methodical.
Step
One: Interview
the Users
I
start talking with the users to see what is wrong. What
are the complaints? I talk with several users to get as
much info as I can. I categorize the results...
Plotting, Opening, Saving, Referencing files, Layers, Functions
not working right. After I have my categories I know what
to start looking for.
I
ask where the files came from. Did we create them from
scratch? Did we get them from someone else? Where
they translated from another program? This lets me know if
there will be a concern based on work that we were not involved
in creating (a big red flag).
I
don't really ask anyone to show me any of the flaws. I
just have them describe the problems. I want to find
things on my own, so I just talk with them at this point.
Many times the manifestation of the problem is not the root of
it.
Step
Two: High Level View
I
take a general high level view of the project. I don't ask
anyone to explain how the project was set up, I just look at the
folders and see if I can figure it out. I look to see if
it follows the Standards as it relates to folder names and file
names. If it differs from the Standard I think that that
is my first indication that the procedures used to create the
files may be haphazard.
Step
Three: Do the Obvious
See
what each of these steps produces. Is the file better
off? Check it after every step.
Now
start checking the files for bad data.
Step
Four: Look at the Master Files
I
open up one of the files and start looking for the
following:
-
Does
it call for any fonts of shape files that are not found
-
Bad
Layer Names
-
Referencing from incorrectly located files
that are not in the project folders
-
Difficult
naming conventions for layers, blocks, hatches, etc.
-
Essential
files (like CTB files) located on local hard drives
-
Settings
that make plotting difficult
-
Incorrectly
used Images
-
Use
of text fonts that are not standard SHX or TTF files
-
Mismatched,
incorrect, exploded and faked dimensions
-
Bad
Viewports
-
Bad
Layout use and setup
Step
Five: Look at the objects
Take
a close look at the objects. I grab them with grips and
look for anything that looks out of place. Are the grips
where you expect them? If not - keep investigating to see
what is going on. I open the properties dialog box to look
for strange things. I look for bad elevations and
"Z" values. A lot of files fail because of
confused elevations and data at incorrect "Z" values.
-
Overly
creative, innovative, advanced functionality
-
Failure
to use OSnaps
-
Inconsistency
– Laziness
-
Bad
block definitions
-
Corrupted
linestyle, multiline definitions
-
Faked
objects to get good plots
-
Exploded
dimensions
-
Element
overrides
Step
Six: Dissect
the file
Copy
the file as another name and start cutting it up.
Detach
Reference files one by one to see if the problem goes
away. Take your time and be systematic. Take notes
of what you are doing if needed. Look for nested XREFs or
circular xrefing.
If
I have a file that opens slowly or takes too long to Regen, then
I start eliminating things until it speeds up. I start
erasing objects in sectors with a window crossing method.
I am not worried about getting the data back since I am working
on a copy of the file.
You
could also erase objects by using filters to select and delete
them. Erase all of the dimensions, then the multi-lines or
blocks. Keep saving and opening the file to see how it is
affected. Purge as you go.
I
usually narrow it down to one object, reference file or block
and can eliminate the data from the original file and keep
moving ahead.
|