I’ve heard the question many times, and I’ve heard a lot of answers. “ESRI’s products make inaccurate maps”, claim some AutoCAD users, while some ArcGIS users feel that “AutoCAD ruins our coverages”. In reality, BOTH families of products are excellent for certain tasks, and not so good for others, but the gap is closing and moving information between them is easier than ever. The following brief history of my experiences with them illustrates this evolution.
In the 1980s, ESRI’s flagship product, ARC/INFO was a clumsy beast requiring a powerful mini-computer, and “help” came from dozens of three-ring binders. While interning at a transportation planning firm, I used it to quickly do the kind of demographic mapping and network/node analyses that had taken much longer to perform by hand. I was sold on GIS as a mapping and analytical tool, but it had a very steep learning curve and an astronomical price.
In the early 90s, I worked for a multi-disciplinary engineering firm and learned AutoCAD, then their only mapping software. While I immediately appreciated the precision and flexibility it offered, I was using it primarily to create maps, so I had to force its features beyond their intended purposes – drawing and hiding many redundant bounding polygons and using hatch patterns to fill large areas, for instance. I also had to “hand-crunch” all of the data I was depicting on my maps. Desktop GIS was still in its infancy (does anyone else remember “PC-Arc/Info”, with its clunky self-extracting archived executables?), and still very expensive.
In the late 90s my employer had ArcView, ESRI’s more affordable, easier to learn GIS product.. I could once again easily produce complex, multi-variate choropleth maps. I was no longer wasting valuable time forcing my tools to do things they weren’t designed for, or calculating hundreds of values by hand. However, precise geometric drafting wasn’t possible, and there were many times when it would have been so handy to just add some additional linework to my base maps. Because ArcView lacked object snaps, COGO or even basic geometric capabilities, (like true arcs), I was forced to go back to my base-map sources and request additional drafting, or worse, fudge it in by hand to get something out the door, knowing it was imprecise.
We now have the best of both worlds. It is now simple to convert between platforms and even “round trip” files without compromising data integrity or accuracy (thanks mostly to the 3rd party conversion solutions offered in both Autodesk and ESRI products). Also, both product families have improved significantly, helping bridge the gap between them. AutoCAD can now easily access and analyze external data, and Autodesk MAP has some basic thematic mapping functions and excellent topology building tools, while ESRI products continue to add more precision drafting capabilities and become easier to use. However, I urge anyone with access to both tools to learn what each does best, and take advantage of their particular strengths. A computer is not a tool; it is a toolbox. Having a variety of tools and knowing which to use for a given task is the mark of a seasoned craftsperson.
It is also very important to fully understand any data obtained from an outside source. If the coverages you get from planners were only intended to analyze regional concepts, for instance, you shouldn’t expect them to fit lot lines described precisely with COGO. Check the descriptions of the data carefully and when in doubt, ask. Often, data better suited to your needs is available.
And finally, I suggest that you seek competent advice before undertaking any project that will involve data and tools with which you are not yet familiar. Cadapult Software Solutions and its partners offer tools and services to help you better structure your data and fully utilize your software to take full advantage of the strengths of both tools. A few hours in consulting fees or specialized training can put you days ahead in productivity.