A Model Is Worth a Thousand Drawings

There's an old adage that goes "a picture's worth a thousand words," and, in today's fiercely competitive manufacturing market, "a 3-D model is worth a thousand 2-D drawings." Seeing something firsthand obviously communicates more information and fosters a greater degree of comprehension than an abstract line representation can. But improved visualization represents only the tip of the iceberg of productivity gains attainable by migrating from 2-D to 3-D computer-aided design (CAD) tools.

Since the introduction of 3-D CAD thirty years ago, many designers and engineers have viewed 3-D CAD in relatively simplistic terms. Solid models are "cool," "neat," and "nice to look at," but rarely seen as competitive necessities, which is why a large percentage of manufacturers continue to use 2-D design systems. Other common misconceptions about 3-D CAD are that it's expensive, hard to use, and difficult to implement.

All of these perceptions rest at the feet of CAD vendors past, many of which touted the benefits of 3-D CAD - faster times to market, lower costs, greater innovation and improved quality - while the technology was still in its infancy. Early 3-D systems required costly UNIX-based hardware, were very expensive in their own right, required extensive training and were incredibly difficult to use. But times change, technology evolves and many product development organizations today are seeing the promise of 3-D CAD fulfilled in dramatic fashion.

 

That Was Then, This Is Now

The idea that 3-D CAD is "cool" as opposed to mission-critical - something that's nice to have and a luxury rather than a crucial competitive advantage - is quickly becoming a relic of the past. At one time, questioning the move from 2-D to 3-D was legitimate because the degree to which manufacturers actually realized the benefits of 3-D varied from system to system. In those days, the primary benefit of 3-D was improved design visualization, which is why many engineers believed those early systems were for making "pretty pictures."

Yet thinking of today's 3-D CAD systems in terms of "pretty pictures" woefully understates the potential productivity gains - from conceptual design through manufacturing and marketing - of 3-D. Today's 3-D systems are more powerful, more affordable and easier to use, benefiting from the development of important enabling technologies, such as the PC and the Windows operating system.

In fact, the return on investment (ROI) for 3-D CAD technology is much more tangible than it was fifteen years ago. Because much more functionality is available for a fraction of the cost, more companies are deploying 3-D CAD and realizing more substantial ROIs.

A recent survey of more than one thousand CAD users confirms the greater ROI impact of today's 3-D systems. The survey showed that of the companies migrating to 3-D CAD software:

• 95 percent reported an increase in productivity.
• 69 percent reported faster time-to-market.
• 90 percent reported one or more of the following:
  • Faster time-to-market
  • Reduced volume of engineering change orders (ECOs)
  • Reduced time spent on average ECO
  • Reduced scrap from design errors
  • Reduced scrap from CAM integration

The results were consistent across different industries and previous CAD systems used. There's no question that 3-D solid modeling is a more efficient, productive and competitive approach to product design. Three-dimensional technology has matured greatly since its introduction and now provides greater benefits to design organizations more quickly because it mitigates or eliminates many of the obstacles and challenges that are a part of doing business in a 2-D world.

 

Overcoming the Challenges of 2-D

By its very nature, 2-D design presents a slew of challenges that impede productivity, extend design cycles and increase costs. Today's affordable 3-D CAD systems resolve these issues either by eliminating them completely or by providing a more efficient solution.

Communicating Design Intent
Engineers use CAD systems to capture and communicate design intent. In 2-D, engineers and manufacturing personnel have to interpret or visualize a flat 2-D drawing as a 3-D part or assembly. Misinterpretation of 2-D drawings can result in a loss of the engineer's original design intent, leading to delays and rework. Three-dimensional systems eliminate the potential for drawing misinterpretation.

Assessing Fit and Tolerance Problems
When working with assemblies in 2-D, engineers cannot fully visualize the fit, interface and function of assembly components from a 2-D layout drawing, resulting in fit and tolerance problems that often go undetected until late in the design cycle. In 3-D, engineers can assess and resolve fit and tolerance problems during initial design.

Handling Large, Complex Assemblies
Using 2-D to design large, complex assemblies comprising thousands of moving parts is tedious, labor-intensive and slow because of the need to manage numerous production-level drawings. With 3-D systems, this tedium is completely eliminated.

Minimizing Reliance on Physical Prototyping
Visualizing the performance of an assembly in 2-D (identifying and resolving collisions and interferences) requires physical prototyping and trial and error. The same process can be done on the computer in 3-D, saving time and dramatically reducing prototyping costs.

Eliminating Lengthy Error-Checking
Checkers spend countless hours checking drawings for errors and fit and tolerance dimensions in 2-D. The drawing-checking process is automated in 3-D because fit and tolerance problems are resolved as part of assembly design.

Creating Instant Drawings
Creating different drawing views (e.g., isometric, exploded assembly, detail, section, etc.) in 2-D requires additional work because the designer has to redraw the design line by line. Most 3-D systems create different drawing views automatically from the solid model.

Making Quick, Easy Design Changes
Making design changes in 2-D can be tedious and time-consuming, requiring that manual changes be made to all drawing views. Whenever a change is made to a 3-D model, the change automatically propagates to all related drawings and associated views.

Configuring Derivative Products or Product Families
It is virtually impossible in 2-D to develop varied configurations of products, assemblies or product families efficiently. Whenever products involve varying sizes, dimensions, weights, or capacities, each assembly must be redrawn separately in 2-D. Using 3-D CAD enables the designer to generate families of part and assembly configurations from a single part or assembly.

Reusing CAD Data Downstream
After the generation of engineering drawings, 2-D data has little value for downstream engineering and manufacturing functions, such as stress analysis, tooling creation and numerical control programming. These processes require 3-D data, which must be recreated from the 2-D data. With 3-D, the original solid model can be used for all downstream applications.

Reducing Analysis Time
Finite element analysis (FEA) requires 3-D data that has to be recreated from 2-D data, adding additional time to the design process. In 3-D, design analysis can be run on the original solid model.

Shortening Manufacturing Cycles
After the initial design phase, 2-D design data must be recreated and manipulated repeatedly to support other processes, such as analysis, prototyping, stereolithography, manufacturing, fabrication and assembly. This adds time to the manufacturing cycle. All of these processes can leverage the original solid model in 3-D, obviating the need to recreate or manipulate design data.

Improving Support for Documentation, Publication and Marketing Processes
Two-dimensional drawings can provide some support for documentation, publication and marketing needs, but in most cases requires additional work to create customized isometric and exploded assembly views as well as 3-D graphics. In 3-D, all graphics, drawings and exploded assembly illustrations can be exported easily from the original solid model.

A Smooth, Comfortable Transition
While most 3-D systems will resolve 2-D-specific design challenges, not all solid modeling systems are created equal, nor are the migration paths all simple and straightforward. Although the benefits of 3-D CAD are well documented, capabilities, utility, ease of migration and ROI potential vary from system to system. Selecting the right 3-D system to meet a company's specific needs may seem daunting because of the myriad of options and packages available. But if manufacturers keep their specific design needs top-of-mind and consider the applicability of the following variables to their design effort, they can make the transition from 2-D to 3-D a smooth, comfortable process that produces dramatic results.

Designing Products with Style
Manufacturers should consider whether they need to create complex models, surfaces and shapes. A 3-D package should certainly handle curves, blends, fillets and unique design features much better than 2-D systems, but some 3-D systems do this better than others. If adding style and improving the attractiveness of products is an important need, manufacturers should assess a solid modeler's ability to meet that need now and in the future.

Bidirectional Associativity and Parametric Design
Bidirectional associativity ensures that all elements of a design, including assembly models, component models, drawings, details and bills of materials, are associated in both directions. In other words, if a change is made to any piece of design data, the change automatically propagates to all other elements, eliminating the need for tedious, manual updates. Likewise, parametric design functionality is crucial to maximizing the benefits of 3-D. A 3-D package should store all features and dimensions as design parameters, enabling designers to make rapid design changes simply by changing the value of a parameter.

Intelligent Geometry
Three-dimensional geometry should be intelligent enough to support other design and manufacturing functions (e.g., machining, prototyping, analysis, assembly management, documentation, etc.) without the need for file transfers, repetitive data entry or clumsy data handoffs. Once a designer creates a 3-D model, the entire product development organization should be able to work with the geometry without recreating, remodeling, redrawing or converting data.

Large Assembly Capabilities
Manufacturers should evaluate their large assembly needs against the capabilities and limitations of different 3-D systems. Can the package handle thousands of parts? How are assemblies managed? Does the system provide tools for design evaluation, such as interference checking and collision detection?

Integrated Add-On Solutions
What's the breadth and availability of integrated add-on solutions, such as analysis, product data management (PDM) and computer-aided manufacturing (CAM)? Are integrated specialty applications available, such as sheet metal tools, optical design applications and tolerance analysis software? Manufacturers should evaluate the number of solution partners for a CAD system, their reputations and the degree of integration provided.

Legacy Data Management
A prime consideration in migrating to 3-D is how the system handles legacy 2-D data. How does the system access and use legacy data? Does it provide data translation formats and tools for converting 2-D design data into 3-D solid models?

Visualization and Virtual Prototyping
The ability to visualize and evaluate a 3-D design on the computer screen can dramatically reduce prototyping costs. Does the package include robust visualization, design evaluation and animation capabilities?

Ease of Use/Training Needs
Three-dimensional systems should be easier to use and require less training than a 2-D package. Consider whether a package is intuitive, requires fewer steps, automates repetitive tasks and provides an open API for customizing certain functions. Designers should be able to use a solid modeler after a couple of days of training and should become proficient with the software in weeks instead of months.

Integration with Desktop Productivity Tools
Is the package integrated with desktop productivity tools, such as Microsoft Word, Excel and PowerPoint? Can the package export design data directly into documents, presentations, and spreadsheets?

Return on Investment (ROI)
Does the 3-D CAD vendor provide a reliable means for calculating the return on your investment in the software?

Company Strength, User Base, Vision
Another important consideration is the vendor's size, industry position, vision and commitment to customer support. Is the company financially secure and is its technology considered to be a design standard?

Customer and Vendor Interaction
Does the package support import and export of common data formats, such as DWG, DXF(tm), IGES(r), STL and STEP, which is an important consideration for interacting with customers and vendors?

Specialized Capabilities
Are specialized capabilities, such as sheet metal, piping, or mold creation required and which package offers them?

Assembly Flexibility and Automation
Manufacturers that produce families of parts and products of varying sizes, dimensions, weights, and capacities, should assess a package's ability to create configurations of assembly variations automatically.

Effective Web Communication Tools
Does the package provide web-based communication tools for easily sharing design data with vendors and customers and collaborating with colleagues and partners?

By taking these considerations into account when evaluating 3-D CAD systems, manufacturers can maximize the productivity benefits of 3-D and facilitate a smooth transition from 2-D to 3-D.

The 3-D-Powered Enterprise
In recent years, 3-D design technology has grown exponentially to provide benefits above and beyond its use as a design tool. The goal in migrating from 2-D to 3-D CAD is to accelerate the rate at which information is processed throughout product development, from conceptual design through marketing. By implementing a 3-D package that supports the entire product development process, manufacturers can fully realize the benefits of 3-D design.

Three-dimensional solid models are much more than "pretty pictures." They are the data thread that weaves their way throughout the entire manufacturing enterprise, producing the efficiencies and agility necessary to compete successfully in a competitive global market. That's why in today's product development environment, "a model's worth a thousand drawings."