Realizing the continued advances in computer technology and 3D CAD, it is a bit odd to consider that even today much product design is still being done in 2D. AutoCAD from Autodesk is still a top seller within the product development space. Autodesk touts many thousands of seats on support within the mechanical space. Why hasn’t everyone switch to 3D design by now? Students are now leaving high-school and college with 3D CAD experience. The software is considerably lower cost and is now much more capable and useable. So why is 2D still being used for mechanical design?
Of course the question is not that simple. Let’s first take a look at the usual transition from 2D design to 3D product development.
- Design with paper and pencil, create detail drawings on paper
- Design with paper and pencil, create detail drawings with 2D CAD
- Design with 2D CAD, create drawings with 2D CAD
- Create 3D models, use 3D models to create 2D drawings
- Design in 3D, use 3D to create 2D drawings
- Design in 3D, virtual prototype and simulate in 3D, use 3D to create 2D drawings
- Digital product development, leverage 3D throughout product lifecycle to reduce/eliminate the need for 2D drawings and duplicated effort
2D has been used for design ever since man started designing things thousands of years ago. It was only recently that we started using computers to assist with the design process. Moving from the drafting board to CAD took some time to get used to but it was not a difficult move once we gained confidence with the computers. Moving to the computer did not involve any change in the process other than we were plotting our drawings rather than blue printing them. The actual design process changed very little.
When 3D first emerged into engineering and product development, it was very expensive and slow. A few early adopters were able to get value from it, but 2D CAD was still the tool of choice for real design work, besides our processes were very dependent on the 2D drawing. While some understood the benefit of designing products in 3D, most systems were justified and purchased on the idea that 3D would provide the ability to speed the process of creating drawings. At this stage many companies made the decision that their products were so simple, from a geometrical view, that 3D would not provide the needed ROI. I have personally been told by several company representatives that their products are so simple that there is really no value for them to move to 3D. Generating the necessary 2D drawings is most likely not the bottle-neck of the overall process for these companies. But are there other benefits to 3D that these companies are missing out on?
There are many companies still with this mindset. They have made the conclusion that the value of moving to 3D does not justify the cost. Obviously these are the two areas we will focus on in this paper. What is the benefit and value of 3D based product development environment, and what is the cost of moving from 2D to 3D? Considering that 3D CAD has now existed for at least 30 years, we should be able to answer these questions.
Using 3D to create Drawings Faster
While some may argue, it is very easy to prove with most any 3D CAD system that you can create drawings faster with 3D than with 2D. Even a drawing for a simple shaft can be created faster in 3D than in 2D. The 3D user simply creates the profile of the shaft and revolves it. You probably need at least 2 views for the 2D drawing. In 3D, these views are created automatically and match exactly. By the time the 2D draftsman has the first view done; the 3D user will have the entire drawing completed, along with a nice 3D representation of the shaft that can be leveraged into the assembly design process, and perhaps other future products. Creating drawings faster represents the most minimal benefit /value of moving to 3D. To understand this value you simply need a stop watch and an understanding of the hourly rate/cost of a draftsperson.
Moving to 3D to create drawings faster does not require a process change. You will need to purchase a 3D CAD tool, but most of the cost will be related to the training required of your CAD users on a new system. There may also be some cost related to the management of 3D models and associated drawings. When selecting a 3D CAD system at this stage we usually consider functionality and ease-of-use as critical criteria. These are important factors, but take note that there are many differences in today’s 3D CAD products that can have significant impact to your design process. It may be wise to get some professional help to ensure that you are putting in to place the right foundation that properly supports your process and business needs. Making the right choices at this stage can greatly reduce the potential for future cost as you mature in the use of 3D design data.
Using 3D to create Accurate Drawings
This represents a much more substantial value than just making drawings faster. With one 3D model, many views of the part can be generated, across sheets if needed. All views will match the model – exactly. There is no possibility that one view is incorrect. An incorrect drawing that goes to production can have substantial costs. At this point drawings are still the master document, but they are entirely derived from the 3D model. To understand the value you will need to evaluate the frequency of errors related to incorrect drawings, and the cost related to the error.
Creating more accurate drawings by utilizing the 3D model is a given, and will require no additional investment, other than perhaps continued education in the use of the tool. As users become more proficient in the use of 3D, 2D views in the drawing are just simple output from the 3D model. It is now just a matter of annotating the views.
The 3D Environment
Using 3D to create Accurate Designs
Now we are approaching a level of value that is not only substantial but also somewhat difficult to measure. In the first two situations mentioned above we are assuming that drawings are being created of good designs. In this case, we are questioning the accuracy of the design itself. Do parts fit together correctly? Are interferences understood? Does the assembly work as it should? At this point drawings may still be the master document, but the 3D model is being used deeper in the design process to ensure accurate designs. We can also begin to formally manage the 3D model and assemblies. BOM’s can be extracted and access controls as well as revision and versioning can now begin to be applied at a part and assembly level rather than just documents and drawings. To understand the value, look in the scrap bins of your manufactures and assembly lines. Also understand the volume of change orders and why they occur. How much rework is being done due to errors in the design of the product?
At this stage there may be some impact to process, although minimal. What can be more of an issue, and cost, are the necessary changes to culture and habits that will be required of the CAD user. Some of this will happen naturally as they grow in the use of 3D. Further training for the CAD user will also be required to take advantage of more of the advanced functionality of the CAD system. Assembly modeling will now be required. Standard part libraries should also be developed and maintained to get full advantage of the system. There may be additional design task specific modules that may need to be purchased. Also at this point, more formal management of the 3D models and assemblies will be required. Without formal management, wasted duplication will occur. Part naming and numbering at the model level will also be required and, if not already done, will require much attention. Drawing numbers will begin to lose their relevance.
Using 3D to support Digital Product Development
As we leverage 3D to support and now drive complete digital product development, value can be a magnitude beyond that of creating accurate designs. It can also be even more difficult to measure, but it is possible. What we can begin to consider at this stage is the leverage of 3D data throughout the product development lifecycle. We can now consider the 3D model as the master, rather than the 2D drawings. All downstream documentation is derived from the master model. Rapid prototyping can be completed based on the master model. Manufacturing and assembly tooling can now be derived from the master model. CNC programs can also be developed based on the 3D model geometry. The effort to develop and maintain fully detailed drawings can be greatly reduced and in many cases eliminated. With the 3D model as the master, the management of information can be greatly streamlined. With formal management of the master model and all related information, everyone will be working on the latest version. Team members are informed of all changes as the development progresses.
As you move to digital product development, process change will be the most significant cost. With process change comes some need to address culture and habits as well. This will also require close interaction with downstream processes, including the supply chain and partners. There may also be additional functionality that will need to be purchased to get to this level. Another significant cost will be PLM. Formal product lifecycle management must be in place to support this level of productivity. It will not work without it. Unfortunately the costs to move to this level can be very elusive. It is greatly dependant on the product design cycle, product lifecycle, product volumes, supply chain, company size and distribution, and key business drivers. Don’t just start throwing tools and technologies in assuming that what works for one company will work for ours. Pay close attention to business drivers and the supporting processes. Otherwise your costs will go quickly out of control – very fast and very big.
At a very high level, the value of 3D can be summed up very quickly. Basically as we work through the various stages identified above, we are simply reducing the potential for duplication of effort, and accompanying error. We are also increasing our ability to leverage existing data downstream, resulting in improved innovation, higher quality and reduced cycle times (to name a few). Sounds a little too simple, but basically that is what it is all about. Consider designing in 2D, if you are designing a part with a hole in it, it is very likely that you are creating a representation of that same hole several times as additional views are added. This is a simple example of where duplication of effort can be eliminated as you progress into 3D design. Consider a tool designer that is using 2D to design the required tooling, if the 3D model is not being leveraged; geometry is certainly being recreated that has already been created at some point earlier in the process. It is very easy to consider countless other possible ways that duplication of effort happens within product development and throughout the product lifecycle. The basic value of 3D is in doing something once and leveraging it to the maximum possible.Consider cost, also at a high level. What must be considered foremost are culture, process and business. In reality the purchase of a 3D CAD tool may be the lowest cost piece of the puzzle. Tools and technologies, including 3D CAD, must enable process and process must deliver on business drivers and objectives. If you start throwing tools and technologies into the mix without considering this, costs can quickly fly out of control. It is important that you start with the right tools and technologies that support your business and process drivers and requirements. As progress is made in the use of 3D, process will need to adjust. However the impact to process can be minimized by selecting the appropriate 3D technology/tool. Often times 3D CAD is purchased based on user preference, ease-of-use or other low-level requirements. Be careful, there are many differences in today’s 3D CAD systems that can have significant impact to process. Select the right tools in support of your business needs.
Take a close look at the state of your product development process. Where do you fit on the chart above? Can you recognize the value and benefit of moving up the chart with your processes? Are the related costs understood?
The chart above from the Aberdeen Group indicates that those companies that are progressing towards digital product development (Best in Class) are realizing significant business benefits. The necessary technologies exist today and there are even standards that have been defined such as ASME Y14.41 to help companies make the move. If you are not already making the move to digital product development, it is likely that your competitors are well ahead of you.