Computer-aided-design (CAD) software has been in existence since the 1960s. The programs ran on mainframe computers, and, because of the high operating cost, the programs were often developed in-house at only the most significant companies. In the 1970s and 1980s, the price of computing power in minicomputers and, later, personal computers began falling to the point where it was economically feasible to put terminals or PCs on the desks of individual engineers. In addition to other computer tasks, such as solving complex mathematical problems, writing reports and simulating products and processes, CAD software was often made available to design engineers. CAD software is not complicated to learn if only doing simple drawings, so rather than hand-sketched electrical diagrams, design engineers could quickly create drawings to hand over to the drafting department to detail and error-check the drawings to turn them into finished documentation.
I am in no way disparaging the infamous drawing on a cocktail napkin; that type of design holds a particular place of importance in the creation of big, new ideas.
Modern CAD software is very customizable. Extensions and additions to the main software package can be made using a supported scripting language. Different engineering disciplines require specific objects to be available. An electrical engineer would have little use for predesigned architectural windows just as a civil engineer would have little use for relay symbols. One way to customize your CAD system is to create or purchase a library of predesigned objects, or blocks. You may then give the block attributes, such as the manufacturer's name, catalog part number, the block’s physical location in a panel or in a plant, several lines of descriptions and so forth. Most all software, CAD included, has third-party add-on applications, or apps, available for purchase or free. These add-ons are created to solve a specific problem for a specific application, or they are provided to promote a particular manufacturer’s products.
Customization of all-purpose software has a few downsides. When using a highly customized version of any software, hiring someone with training and experience with your particular software package requires an additional learning curve to become familiar with all of the customization and how it is used in your facility. Usually, the task of creating new functionally in a software package by writing custom scripts, or apps, is left to a small number of individuals, or even one individual within an organization. If an essential individual leaves, it can take some time to replace that individual with another who has the same skill level and can extend and support the customization. With most all custom software, bugs appear from time to time. Will the bugs be dealt with promptly, or will they be fixed when time becomes available for the person who does that sort of thing?
Some CAD software manufacturers create discipline-specific versions that include functions not available with the main general-purpose versions. Electrical, mechanical, civil and others are designed to be used within a specific industry. Electrical CAD may provide things such as automatic bill-of-material generation, a wire object as opposed to a line object, coil and contact cross-referencing and automatic wire routing. There are additional features an industry-specific CAD software program offers versus the standard software version that are not discussed here. Various manufacturers hype a variety of features and functions in their software, so check out the detailed websites and sales brochures.
It’s sometimes tricky filtering out the noise when investigating the pros and cons of a software product. The size of the project and the types of documents to be produced are a much better guide than the opinions of various anonymous forum posters. From an informal poll, the most common answers as to why not use electrical CAD software as opposed to using the more specialized are, in no particular order:
that is what we always used
because the manager tells us to use it
the cost of the electrical CAD version is too high
our customers tell us to use it
our software is too customized to start using something else.
In the end, it is all about productivity. Most any drawing software can be used to create wiring diagrams and panel layouts. Comparisons between different packages are available on the Internet. Keep in mind the software that compares most favorably is quite possibly a sales tool created by that software’s manufacturer. Using an industry-specific version of CAD software offered by the manufacturer should include support from the manufacturer to address bugs, customer-requested extensions and support for new operating systems and computing platforms.
If you do wish to migrate from vanilla CAD to electrical CAD, you should expect to incur additional training costs. Though a person may be an expert with the general CAD version, the electrical CAD version will require a slightly different mindset to make full use of the additional functionality, but the cost should not be significant. The manufacturer is not going to create a whole new user interface or dramatically change the experience of using the software just for the electrical-CAD version.
Moreover, I have heard of no end-of-service date for cocktail napkins.