INTRODUCTION
It may have happened to you. Now and
then you have wandered to the drawing closet to locate a specific
engineering drawing and returned to your office seat exhausted,
dusty, frustrated and empty handed. Paper drawings are simply
inherently difficult to locate.
You might consider scanning your
engineering drawings and maps to make finding them easier. In fact
scanning your drawings provides enormous, including:
· Protects drawings from fire,
water and age hazards
· Permits quick and easy access by all staff
· Facilitates faster conversion into a true CAD file on a as
need basis
· Enables second generation prints to be made on demand
START BY SCANNING YOUR ENGINEERING
DRAWINGS
Any electronic type of
storage/retrieval system will require a digital copy of your
drawings. There are many decisions that must be made at this time,
but most have become informal industry standards. Typically
engineering drawings are scanned to the following basic
standards:
· Optical scanned resolution
400 dpi in tif group 4 format
· Black & white (2 bit colour)
· De-speckled (small speckles introduced from scanning are
removed)
· De-skewed (rotational errors introduced by mis-feeds into the
scanner removed)
· Drawing that are in extremely poor condition may require
custom image cleanup to obtain a useful image
Basic scanning of drawings is
relatively cheap, a good budget figure would typically range from one
to three dollars per drawing, depending upon quantity, condition and
related factors. You may not want to go any further than this step if
you have a small number of drawings, say around 100. If you have
hundreds or even thousands of drawings you will probably want to go
one step further.
MANAGEMENT OF SCANNED DRAWINGS
If you decide to scan your drawings,
that's a great first step. Why not go one step further and index you
drawings to make locating the needed drawing efficient. There are
many options available to you at this point, and some of these are
discussed below:
Index drawings using database software (EXCEL, ACCESS,
FILEMAKER PRO)
Prior to scanning each drawing a
unique bar code or identifying sticker is attached to the drawing.
This number along with information about the type of drawing, its
title etc is entered into a separate database. The bar code number is
used as the drawing filename facilitating locating the scanned
drawing file based on any of these criteria. For example it would
make sense to enter the following on each drawing and relate this to
the bar code number attached to each drawing.
· title of drawing
· drawing number or contract number
· date of drawing
· street or building particulars
· type of drawing
· drawing number from bar code
A sample of what this might
look like is illustrated below
FIGURE 1
Figure 1: A completed MS ACCESS
database along with a reduced resolution thumbnail of the drawing
embedded into the database.
If you already have the
software (ACCESS etc) then this option is very cost effective as it
eliminates the cost of acquiring software to manage the scanned
document database. One disadvantage of this system is the need to use
another software system for viewing and printing your documents.
Software to view and print your images varies in price significantly
(from nearly free to hundreds of dollars); however if you already own
AutoCAD why not use it as a drawing viewer, further reducing the
software (and therefore costs) you need to purchase.
AutoCAD (v 14 and above) reads
scanned images and can scale, rotate and print them for you. In
addition, you can retrace the scanned drawing once loaded into
AutoCAD, and with an investment in labour have a completed "true"
AutoCAD file of your drawing.
While potentially having the lowest
NEW capital software investment, if you already don't own
ACCESS/EXCEL and AutoCAD and know how to use them on a basic level
then this option may not be as effective (in terms of money and
productivity) as the other options listed below.
INDEX DRAWINGS USING VERTICAL MARKET
SOFTWARE
There are a number of software
programs that can be purchased that are designed specifically for
indexing, management and retrieval of scanned documents. This option
provides the comfort of a dedicated system of managing your drawings
from established vendors. Some of these systems have the ability to
convert scanned images into vectored CAD files, permit measurements
and have advanced printing and management controls that should not be
discounted.
Should you have a small number of
drawings however, the software costs may exceed the scanning and
indexing costs. Therefore this option becomes more cost effective as
the number of drawings increases. Purchasing additional licensed
seats for the staff, and updating the software periodically are
additional, some time "hidden" costs of this system of drawing
management that can reduce its cost effectiveness.
INDEX DRAWINGS USING HTML
HTML can also be used to manage your
drawings. One technique that might be used is to have the drawings
scanned, then have the vendor employ several levels of dithering of
the original images through bulk processing of the files. These
companion files would be used to provide additional functionality as
discussed following.
An index web page (figure 2) might
use a map of your community as the interface to your drawings. By
indexing each drawing (for example), to the part of the road on the
map they represent an effective system of locating your files can be
constructed. When you click on the area of road (or feature) you are
interested in, a html web page (figure 3) would appear outlining
information on the drawing. This page could have a reduced resolution
thumbnail of the drawing and provide a link to a dithered 8.5 by 11
inch version of your drawing suitable for printing on the laser
printer. A link to the original scanned document could also be
provided should you want to access it.
Figure 2: Example of index web page
from html based storage retrieval system. Users click on drawing of
interest to view it. Click here or on image for
a demonstration.
This system obviously will entail
setup costs that vary significantly depending on the functionality
built into it and the chosen vendor. Therefore costs are highly
variable. However this system does not require you to stick with a
specific vendor, require staff training or necessitate additional
fees to purchase more licensed seats.
When new drawings are obtained they
would be added to the system and this would involve additional costs.
However using the html standard would permit any Web consulting firm
to do the update, promoting competitive pricing and long term system
life.
WHEN COST & SIMPLICITY MATTER MOST
Are cost and simplicity of most
importance to you? If so, there may be no better way than to index
the scanned drawings in Excel with a three to six field database, and
hyperlink each record in Excel to individual AutoCAD files that have
the embedded scanned images placed in them at their correct scale.
Imagine - perhaps no staff to train, having the images in a program
that can print them out, measure from them, and the ability to trace
over them. Best of all - perhaps no software to buy or new software
to learn and the option of doing most of the work in-house!
There are many subjective and
objective variables to be consider in making a decision that's best
for you. All techniques discussed safeguard your investment in
Engineering drawings and permit you to retrieve them in digital form.
The primary differences being the software programs used to
facilitate this, their functionality and the cost/training involved
to take advantage of the functionality.
This author recommends choosing the
simplest system that is on par with your Municipalities internal
skill sets, budget and needs.
About the Author
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Randy Kowal is Principal of
dartmap.com an Engineering Drawing and Mapping Specialty
company located in Whitby Ontario.
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