AutoCAD for SurveillanceBy Brian Rhodes, Published on Sep 24, 2012
While the construction industry made the transition to computer aided design software years ago, many in security have yet to do so. Perhaps because they seldom need to use CAD programs during work, many still use manual paper sketches or simpler applications to plan designs. However, many projects now required 'as-builts', or installation drawings, as part of the project scope. Choosing the right program to standardize on is risky, but in this note we cover the largest, safest choice of all, AutoCAD, looking at both its strengths and weaknesses.
AutoCAD's Biggest Value: Market Share
The 'biggest name' in Computer Aided Design software has widespread acceptance. Since AutoCAD's introduction in the early 1980's, parent company Autodesk has aggressively acquired many competitors and companion softwares, and as a result AutoCAD has 'bought into' many specific markets and applications.
Compared to other, industry specific CAD programs, AutoCAD's primary attribute is that is can be applied to many markets, from machine design to architecture. Because of that diversity, many drafting schools standardize on teaching the program because it attracts larger eligible groups.
In terms of interoperability between CAD programs, because AutoCAD is so widely used, it stands the best chance of being immediately compatible with 'source' drawing files and eliminating costly redraw time. Most master blueprint sets are created using AutoCAD, therefore it permits creating surveillance 'as-built' drawings with minimal interoperability issues. Producing 'as-builts' can take minutes, not hours when drawn natively in AutoCAD versus redrawn in other programs.
Strongest Drawing Features
Aside from having the biggest CAD market share, AutoCAD's strongest features are numerous smaller details not found in other programs. Together in one program, these features that make it useful for surveillance work are:
- Layers: This is the foundation of modern CAD blueprints. A 'drawing layer' gathers all line drawings and details relevant to a building and makes it possible to be easily managed. For example, all the 'plumbing' details are located on their own layer, as the same with 'masonry' or 'electrical'. In this way, 'video surveillance' or 'security systems' can be drawn on their own layer without needing to redraw or copy basic details. Drawing revision management is much easier when all 'layers' reference each other, and producing 'as-builts' is often as creating a new layer that overlays existing details.
- Precision: AutoCAD supports measurements to more than 50 decimal places. This precision is suitable for advanced engineering design work, and considering that tolerances in security system design seldom dip below one or two decimal places, the software is more than 'precise enough' for surveillance use.
- Symbols: Regardless if they are called 'symbols', 'blocks', 'stencils', or 'shapes', having a pre-drawn label that can be copied and pasted into layouts is a time-saving feature. AutoCAD symbols are very common, and more widely available than similar equivalents in other programs. In some cases, manufacturers provide 'free' AutoCAD symbols to help speed up the drawing process and improve accuracy.
- Scale: AutoCAD maintains drawing scale, both during drawing and reproduction. This is critical for producing useful and compliant 'as-builts' to accurately gauge size and distance of system features.
- Printer/Plotter Support: The 'large format' support common to construction blueprint sets, like ANSI C, D, E and F print sizes is native to all versions and variants of AutoCAD. In addition, the program includes a 'Print to PDF' driver that allows for electronic copies to be drawn and sent in large sizes even if no plotter is present.
- Filetype compatibility: The substantial majority of modern CAD programs support the .dxf, or 'universal drawing exchange format'. Akin to ONVIF, no matter the 'source' CAD drawing application, it can be read and modified in AutoCAD when saved in .dxf format.
- 3D Capable, but not Required: AutoCAD is natively 3D, and generating complex drawings like Riser Diagrams or 3D rendered elevations are possible. However, because construction blueprints are not commonly drawn in 3D, less expensive versions of AutoCAD are available that omit this element.
Expensive by Comparison
The cost of AutoCAD, in terms of both software cost and user training cost is high. While it is the most 'general' drawing tool, it also contains features like part modeling, mechanical design tools, and dimensioning features that are simply wasted on surveillance system work. Not only is paying for these unneeded features costly, the extra features add complexity to the drawing interface.
That complexity also makes it more expensive to use. While finding an entry-level draftsman with AutoCAD knowledge is not difficult, AutoCAD is not considered a 'self-teachable' drawing program like Visio, or industry specific programs like JVSD or Pelco's 3D tool. Paying for additional training can cost more than $300 and take several weeks of classwork to gain rudimentary skills in using the program.
Software Cost: The most basic, general version costs ~$4000 USD. For those not requiring 3D modeling capability, AutoCAD offers an 'LT' version that typically costs ~$1100 USD. Unlike many other CAD platforms, however, AutoCAD does not require ongoing software licensing for use, but does offer a yearly Software Maintenance Agreement that is about 20% the cost of a new license and results in up to 90% reduction in price when upgrading.
When contrasted with the cost of Microsoft's Visio, that retails for ~$500 USD and can be easily learned, AutoCAD requires significantly more resources to deploy. However, Visio cannot be used to modify native AutoCAD files, nor does it have the flexibility to modify 3D designs.
If a security integrator performs a large number of installation projects, has a dedicated draftsman, and is required to produce a large number of "as-built" drawings, AutoCAD can be an irreplaceable application due to its flexibility and widespread use in the construction industry.
However, unless smaller installers/dealers already have multi-skilled operators trained in AutoCAD's use, the program is overkill for most security projects. For smaller integrators, Microsoft Visio (see our review for more details) or other less-advanced drawing programs are regularly used.
For small or medium integrators, AutoCAD is likely overkill for developing as-built drawings. (See out Creating 'As-Built' Drawings for more details.) In most cases, paper blueprints with handwritten markups are acceptable as-builts drawings, and converting those to CAD drawings typically is the domain of the A&E making record drawings.
AutoCAD is a staple for reviewing Blueprints and even developing estimates, but it is not generally necessary for project performance.