New Approaches to CAD "Integration" - computer-aided design products from Vistagy Inc., 3Ga Corp

Automotive Manufacturing & Production, June, 2001 by Lawrence S. Gould

Getting worldwide access to product definition and solid modeling data is not a trivial problem. Here are two CAD products that take two very different approaches to accessing parts proudct data.

Two capabilities are absolutely critical in today's wired, follow-the-sun design engineering world: collaboration and interoperability. These are not necessarily mutually exclusive capabilities. To a large extent, you need interoperability for collaboration to happen.

Two computer-aided design (CAD) products addressing these very issues are sufficiently new and different to warrant closer inspection. Both let designers collaborate across disparate CAD systems. Both also let "asynchronous collaboration" happen. One, EnCapta from Vistagy Inc. (Waltham, MA) is a plug-in that adds non-graphical information to a solid model. The other, 3G.web.decisions from [3G.sup.a] Corp. (Los Angeles, CA), merges two extremes in computer networking architecture to let users evaluate designs based on multiple parametric changes.

The plug-in approach

Engineers collect "pages and pages" of non-geometric information (e.g., costing, material, tooling, testing, and other data) in the process of creating product geometry, says Steven Luby, Vistagy's president and CEO. Little of this can be expressed or managed efficiently in a conventional CAD system. In fact, much of this information is unstructured and on various media: drawings, spreadsheets, email, hand written notes, and more. Such information is hard to retrieve, analyze, and pass around to other decision makers.

Ideally, product data management (PDM) systems solve these problems by being a repository for that data. But, asks Luby rhetorically, "are you finding the product information?" The response is often "no," even moreso when you want to do something with the product data--other than design. Sure, the CAD model data is easily accessible, but what about all the other product definition data?

Many companies, continues Luby, write custom "wrappers" around their PDM systems to extract specific information for specific uses. For instance, a procurement manager may want to know about coatings, tolerances, and heat treatment specifications that are called out on a drawing--a drawing!--in the drafting part of the CAD model. More to the point, says Joel Orr, Chief Visionary for Cyon Research Corp. (Bethesda, MD), when you're following manufacturing instructions, you really want all the information and graphics to be together.

There has to be a better way to capture a complete product definition and distribute it throughout an enterprise. Luby says he's got that better way: Put all the data within the 3D model. Which, not surprisingly, Vistagy's EnCapta lets you do. This plug-in lets CAD designers and engineers add and associate non-graphical, non-geometric information to CAD geometry--and store it with the CAD geometry. EnCapta provides, continues Luby, "the context necessary for interpreting the rest of the CAD model." Adds Orr, "EnCapta basically adds functionality to CAD systems that naive users might have thought was already there."

EnCapta consists of three main components: customizable templates, an interactive user interface, and extensible Markup Language (XML) tools. Engineers use the templates to create EnCapta "objects," which are basically definitions for the type and structure of specialized information they wish to capture. Data such as design details, cost estimates, engineering change orders, material specs, and assembly instructions can all be EnCapta objects. These objects get linked to relevant CAD geometry. Individual EnCapta objects can reference multiple geometric features; conversely, multiple objects can reference a single geometric feature. The templates help ensure that the correct information is in fact recorded and stored. Better, the templates need only be defined once, regardless of underlying CAD system.

The user interface invites engineers to browse these EnCapta objects and display the associated geometry. Alternatively, engineers can click on a part in the CAD model to display the associated non-geometric data, now EnCapta data. Without leaving the CAD system, engineers can view, edit, sort, and search the design and manufacturing information associated with the geometry. Because these objects and the data within them are associative to the CAD model, it isn't necessary to re enter data, such as a material's thick ness, after making design revisions.

The XML tools act as a release valve for specific design data to leave EnCapta for other applications, and vice versa. This XML port can be set up as an automatic import/export; however, that winds up being yet one more link in the interoperability chain. Considering how software vendors are currently going ga-ga over XML--and for good reason--this extra link may be a "non-issue."

Also a non-issue is the size of the additional non-geometric data in the CAD model file. "If it's 5%, that would be a lot of information," says Luby.