Once a 3D PDF is opened and the 3D content is activated, we are presented with a wealth of information such as product and manufacturing information (PMI), texts, images, 3D viewports, predefined views, tree nodes and attachments. How can we take full advantage of this rich content? Let’s look into the PMI first in this article.

3D dimensions and tolerances attached to models are an important step in model-based definition (MBD). They convey critical engineering and manufacturing requirements, so it’s vital for downstream consumers to understand and act upon them correctly. One common problem, though, is how to relate a 3D callout to its associated features. A leader line pointing to a feature can help, but it doesn’t point to a group of features such as a pattern of multiple instances. And a leader line may sometimes be obscured by the model body. To illustrate the relationship between 3D callouts and their corresponding features, the ASME Y14.41-2012 standard requires the “visual response” capabilities. That is, when you click on a 3D callout, not only should the callout be highlighted, but also should the corresponding features it defines. SOLIDWORKS MBD supports this cross-highlighting behavior as shown in a previous post, “Top SOLIDWORKS MBD Tips and Tricks: Hole Callouts.” One step further, the 3D PDF published by the software also complies with this requirement as shown in Figure 1. This model can be downloaded at the National Institute of Standards and Technology (NIST) website. Please note that cross-highlighting only works in one way—from 3D callouts to features—not the other way around. The reason is that a feature, especially a datum feature, could be heavily referenced and lead to too many remotely associated 3D callouts. The highlighting is to let a few items stand out from the rest, but if too many items were highlighted all together, it would defeat the purpose of this differentiation.

Figure 1. Selecting one callout highlights all the countersink hole pattern instances in red in a 3D PDF.

The cross-highlighting behavior works on mobile devices too as shown in Figure 2.

Figure 2. 3D PMI cross-highlighting in green on an iPad.

Another common problem with viewing 3D geometric dimensions and tolerances (GD&T) is to envision the datum features. We need to know where datum features A, B, C or D, E and F are in order to make sense of a feature control frame. However, these datum symbols may not be visible or easily legible from the current perspective. So oftentimes, we have to search through multiple views, and rotate and zoom the model to locate these datum symbols. Then we need to remember what they point to as datum features. Finally, we must establish the reference frames to interpret a geometric tolerance. This issue is further compounded by multiple datum reference frames in complex models. To solve this problem, the 3D PDF by SOLIDWORKS MBD provides a context command, “Highlight associated datums,” when you right-click on a feature control frame as shown in Figure 3.

Figure 3. Highlight associated datum features in a 3D PDF.

Now three datum features are highlighted in red, along with the positional tolerance control frame callout and its associated hole pattern on the base plate, as shown in Figure 4.

Figure 4. Three datum features (the bottom face, a bigger mounting hole on the left and a smaller hole on the right) are highlighted automatically.

You may have noticed another context menu command, “Highlight associated PMIs,” in Figure 3. This command highlights the corresponding hole diameters and the constructive basic dimensions for this positional tolerance as shown in Figure 5.

Figure 5. Highlight associated PMIs in a 3D PDF.

These cross-highlighting behaviors can help retrieve key information quickly, confirm the desired features and speed up the comprehension of and executions according to the 3D dimensions and tolerances.

Besides 3D dimensions and tolerances, tables are also often used to organize scattered bits and pieces of information. Bill of materials (BOM) is one of the most frequently used cases. Figure 6 shows the bidirectional cross-highlighting between a 3D viewport and a BOM table. You can click on a component in the viewport, and then the corresponding line item in the BOM table will be highlighted such as the line item number 10, tubing top section, shown in Figure 6.

An engineer once asked me what would happen if a line item was not displayed yet in a long BOM list. The answer is that you don’t have to manually scroll up or down the list to locate it. Your click on a viewport component will automatically find its line, scroll the list to make it visible and then highlight it.

Please notice that the cross-highlighting here is bidirectional. Clicking on an item in a BOM table will also highlight the corresponding components in the viewport. This can help you to locate a component in the way you prefer, either from a viewport or from a BOM table.

Figure 6. Bidirectional cross-highlighting between a BOM table and a 3D viewport.

A SOLIDWORKS MBD 3D PDF can also be published with generic tables saved from the software. Figure 7 shows a simple title block in a published 3D PDF. And Figure 8 shows the insert generic table command inside the 3D PDF template editor. Once a generic table is defined onto a 3D PDF template, the linked custom properties in the table will be automatically populated with the actual model values during the publishing step.

Figure 7. A title block published per an inserted generic table (top).

Figure 7. An inserted generic table in the 3D PDF template editor.

The article, “How to publish a 3D PDF with SOLIDWORKS MBD,” explains more details about the publishing steps. Another blog post, “How to Use 3D PDFs,” will walk you through the basic tools available in Adobe Reader. Last but not least, you may also download several 3D PDF samples published by SOLIDWORKS MBD at a forum post. I’d love to hear your feedback on publishing and consuming 3D PDF in the comment area below. To learn more about how the software can help you with your MBD implementations, please visit its product page.

About the Author

Oboe Wu is a SOLIDWORKS MBD product manager with 20 years of experience in engineering and software. He is an advocate of model-based enterprise and smart manufacturing.

Traditionally, 3D CAD data has been treated in a way similar to a black box. The reason is the data is often constructed in proprietary CAD formats or neutral formats that need special CAD licenses or viewers to read. This black box of data obviously imposes a communication barrier.

A machine shop shared with me its typical way of handling 3D CAD data. A salesperson interfaces with clients and gets 3D data in order to build quoting packages. However, he or she may not be able to read the data. Either the person doesn’t have the CAD licenses, which could be expensive, or a CAD viewer cannot be installed due to IT administration restrictions. Or the viewer may simply be out of date. As Casey Gorman with Sparton put it in a presentation that shared MBD implementation experiences, a CAD viewer may be free, but its ongoing IT maintenance is certainly not. Therefore, oftentimes, a salesperson has to pass along the 3D CAD data to an internal engineer and wait for the engineer to crack this black box with the right CAD tools and extract the requirements. Finally, the salesperson can put together quotes and reply to the clients. If this kind of back and forth communication seems slow, the delay can only get compounded when a salesperson travels all the time and can’t work side by side with an engineer in the office. In short, this 3D communication barrier increases the cost of doing business and prolongs cycle times.

Wouldn’t it be nice if this barrier could be lowered so that more job functions outside of engineers could consume 3D data? This is exactly the benefit of 3D PDF, or a PDF file embedded with 3D content. All we need to read a 3D PDF is a free Adobe Reader, which has been installed on 93 percent of Internet-connected computers globally. So when you send out a 3D PDF file to a sourcing manager, a salesperson or a supplier, most likely they have Adobe Reader installed on their computers already and can therefore open it right away to read the 3D data as shown in Figure 1 with no special viewers required. As explained in a previous article, “3D PDF Enhancements in SOLIDWORKS MBD 2016,” each of the viewports below supports pan, zoom and rotate of the model. It also includes a series of predefined views, 3D dimensions and tolerances, custom properties, bill of materials (BOM) tables, images and attachments. The 3D PDF communication saves not only the software costs, but also the deployment and IT administrative overhead.

Figure 1. A 3D PDF example.

Even better, there are free 3D PDF reader apps for Apple and Android mobile and tablet devices as shown in Figure 2. Now the salesperson on the road whom I mentioned earlier or other job functions who are not often at their computers can consume 3D data and extract key requirements conveniently.

Figure 2. 3D PDF readers on an iPhone and an iPad.

However, before you start jumping into 3D PDF, I’d like to share several reminders.

1. The 3D PDF by SOLIDWORKS MBD works best in Adobe Reader on a desktop computer. There are many PDF readers that support 2D content well such as texts and images, but not necessarily 3D CAD data. Even the Chrome Internet browser can read PDF files today, but it disables the 3D content in a 3D PDF. This becomes especially frustrating when you click on a 3D PDF link inside Chrome. The browser will take precedence over Adobe Reader to open the file, but does not support 3D content at all as shown in Figure 3 where the 3D viewports are all blank. Many engineers have complained and doubted 3D PDF due to this misunderstanding.

Figure 3. Disabled 3D content in a 3D PDF in Chrome.

2. The first time you open a 3D PDF, Adobe Reader holds off the 3D content with a security control as shown in Figure 4. You can choose to trust this document one time only or always by clicking on the Options button on the right side of the yellow warning bar.

Figure 4. An Adobe Reader security control disabled the 3D content in a 3D PDF.

Or you may set the application preference as always Enable playing of 3D content as shown in Figure 5.

Figure 5. Enable playing of 3D content in Adobe Reader.

3. After Reader XI, Adobe released a new version, Reader DC, in April 2015. Both versions work well with 3D PDF. I just find the 3D product manufacturing information (PMI) selection became easier in Reader DC. For example, in Figure 6, the mouse cursor is clicking in the empty space inside the box of a basic dimension 20 mm in Reader XI, but it isn’t able to select this dimension. You have to click exactly on the numbers, letters, lines or curves to select them. In Figure 7, the same click at the same spot in the same 3D PDF using Reader DC has successfully selected the dimension and highlighted the corresponding hole features.

Figure 6. The PMI was not selected in Adobe Reader XI.

Figure 7. The PMI was selected successfully in Adobe Reader DC.

4. There used to be a 3D PDF technology based on the universal 3D (U3D) format, which has not been updated for almost 10 years. So please be careful with this dated format. The 3D PDF by SOLIDWORKS MBD is based on the latest ISO 14739-1: 2014 standard. It also complies with Long Term Archiving and Retrieval (LOTAR) requirements.

With these reminders, please feel free to download several 3D PDF samples published by SOLIDWORKS MBD at a forum post. To find out more details on the publishing steps, please follow this blog post, “How to Publish a 3D PDF with SOLIDWORKS MBD.” I hope this article can help you get started with 3D PDF. We will look into other key aspects such as views and PMI at a later time. To learn more about how the software can help you with your MBD implementations, please visit its product page.

About the Author

Oboe Wu is a SOLIDWORKS MBD product manager with 20 years of experience in engineering and software. He is an advocate of model-based enterprise (MBE) and smart manufacturing.  

1. Define 3D product and manufacturing information (PMI) with greater flexibility
2. Organize 3D PMI more efficiently
3. Publish 3D PDF with better ease of use and closer regulatory compliance
4. Streamline enterprise-level processes

Now let’s drill down.

1. Define 3D PMI with Greater Flexibility

In a previous article, “Design for Manufacturing: How to Define Features Directly,” we illustrated that SOLIDWORKS MBD was focused on annotating comprehensive features rather than basic geometries. While defining features matches the actual manufacturing processes more closely, many engineers would also like to define supplemental geometries besides features.

For example, one designer told me that they need to call out the distance between the center of mass on a robot and the ground level in a factory where the machine is to be installed. The higher the center of mass is, the more likely the robot could tip over; and so, the stronger the mounting structure needs to be. However, center of mass is not a feature. It’s a theoretical geometry. The ground level is an external reference plane, certainly not a feature on the design either. So, clearly there is a need to dimension to reference geometries. Another consideration is to follow 2D drawing conventions. In the 2D world, we can dimension to centerlines or reference planes very easily. Many engineers want to carry over this flexibility into 3D PMI definitions.

Now MBD 2017 includes this flexibility. As shown in Figure 1, you can select the center of mass and a ground-level reference plane to call out the vertical height. Similarly, you can call out the horizontal offsets between the center of mass and the center of the supporting base mount. These are all insightful indicators of an object’s risk of tipping over. Of course, as the robot arm moves, these distances update upon a model rebuild, so that you can monitor these parameters dynamically and optimize the design accordingly.

Figure 1. The vertical height and horizontal offsets of a center of mass.

Another challenge many engineers experienced before was defining drafted parts that are very common in casting and forging processes. As shown in Figure 2, the tricky point is that the 2-degree draft angle generates different diameters at different lengths from left to right on the highlighted extrusion. In other words, one size doesn’t fit all here. To address this challenge, MBD 2017 now assists you in creating intersection circles between the drafted cylinder and reference planes at selected section locations. Then these circle diameters and locations can provide accurate and context-relevant measures to describe a drafted part. The animation in Figure 3 illustrates these quick steps.

Figure 2. Define the diameters and locations of intersection circles on a drafted part.

Figure 3. Steps to create a reference plane and an intersection circle to describe a drafted extrusion.

2. Organize 3D PMI More Efficiently

As we discussed in a previous article, “How to Present the MBD Data of a Gear Box Assembly,” people do judge a book by its cover. So it’s extremely important to present MBD data in a consumable, actionable and professional fashion. In MBD 2017, more tools are available to help organize 3D PMI.

For example, a blog post summarized a handy tool, 3D View, released in MBD 2015. In this new release, 3D View has been enhanced and can now be resequenced by a simple drag-and-drop operation as shown in the animation in Figure 4. The benefit is that you can first capture a group of random 3D Views and then easily adjust their order later. Because of this freedom, you don’t have to be overly concerned about their initial sequence. It also allows designers to fine-tune a storyline inside MBD to guide downstream consumers in a more concerted and structured way.

Figure 4. Resequence 3D Views.

In the 3D PMI presentations between multiple revisions, the most actionable insight is the changes. A tolerance change can drive many critical decisions. For instance, a 0.05-inch tolerance can probably be achieved in house, but a 0.001-inch tolerance probably has to be outsourced at 10 times the in-house cost with many scraps. PMI changes, or essentially requirement changes, affect many areas of the manufacturing process such as the resource planning, the production routing, the tooling and fixtures, speeds and feeds, the inspection setup and reports, costs, the cycle time and so on.

In order to quickly identify the 3D PMI changes in a consumable and actionable way, MBD 2017 provides a new tool called 3D PMI Compare as shown in the animation in Figure 5. The changes can be reported in a separate HTML file for data consumers who may not have SOLIDWORKS installed, such as inspectors, sourcing managers or suppliers.

Figure 5. Compare 3D PMI differences between two revisions.

3. Publish 3D PDF with Better Ease of Use and Closer Regulatory Compliance

3D PDF lowers the communication barrier and so is an important communication tool in MBD processes. MBD 2017 greatly enhances the 3D PDF template editor so that you can produce more professional documents more easily. The animation in Figure 6 shows several handy tools such as alignment, grouping and display order. Please check out the new release to look into more nice additions such as richer text formatting, the format painter and rectangles to organize texts.

Figure 6. Edit the alignment, grouping and display order on the 3D PDF template editor.

It’s also worth noting that you can now resequence sheet orders with a simple drag-and-drop operation. Furthermore, the first sheet doesn’t have to contain a 3D viewport anymore. For companies that must show certain regulatory statements, disclaimers or warnings on the first page of a 3D PDF, this enhancement is exactly what is needed.

4. Streamline Enterprise-Level Processes

With all the above setup, including PMI definition, organization and PDF publishing, now it’s time to visit the model-based processes at an enterprise level. MBD 2017 brings along several key improvements in this regard. First of all, the 3D PDF publishing step has been added as a SOLIDWORKS PDM task as shown in Figure 7. Now you can simply pick a 3D PDF template and the views to include and then kick off the automatic publishing for multiple files, rather publishing individual files manually one by one.

Figure 7. SOLIDWORKS PDM 3D PDF publishing task.

Second, MBD 2017 can now publish the STEP 242 neutral format with 3D PMI based on the ISO 10303-242:2014 standard as shown in Figure 8. Even better, when publishing a 3D PDF, you can check the box “Create and attach STEP 242” so that you don’t have to worry about missing or mismatched attachments in a 3D PDF package.

Figure 8. Publish STEP 242 (left) and automatically attach STEP 242 to a 3D PDF (right).

Last but not least, eDrawings 2017 can display 3D PMI from STEP 242, Creo (Pro/Engineer) and CATIA V5 formats as shown in Figures 9 and 10. Many suppliers to the aerospace and defense enterprises such as Boeing, Airbus and Gulfstream can benefit from these enhancements. In recent years, these large enterprises are sending out 3D models with PMI to replace 2D drawings, so the small manufacturing firms in their supply chain urgently need a tool to read the critical PMI and requirements from the models instead of 2D drawings.

Figure 9. STEP 242 3D PMI display in eDrawings 2017.

Figure 10. Open Creo (Pro/Engineer) and CATIA V5 formats with 3D PMI in eDrawings 2017.

We touched upon several new features in SOLIDWORKS 2017. Table 1 lists a quick summary. To learn more about how this new release can help you with your MBD implementations, please visit the SOLIDWORKS 2017 launch site.

Table 1. Examples of SOLIDWORKS 2017 new features.

About the Author

Oboe Wu is a SOLIDWORKS MBD product manager with 20 years of experience in engineering and software. He is an advocate of model-based enterprise (MBE) and smart manufacturing.  

1. MBD further automates manufacturing with software-readable product and manufacturing information (PMI)

Let’s start with computer aided manufacturing (CAM). CAM software programs read CAD models to automate numerical control (NC) code generation. The benefits of CAM have been proven and this automation has been widely adopted.

However, there is one problem: Some key requirements, such as tolerances and surface finishes, are typically defined and presented in 2D drawings. In most cases, CAM software cannot read drawings, so manufacturing engineers have to look back and forth between drawings and CAM programs to manually extract and re-enter these requirements. This step not only slows down the process, but also introduces data duplication, human interpretation and re-entry errors.

One solution to this problem is to define software-readable PMI directly in 3D models, rather than in 2D drawings. This is exactly the gist of MBD. This way, CAM software can automatically read and act upon the 3D PMI. This automation avoids human interpretations and data re-entries, which speeds up production and reduces errors. Figure 1 shows CAMWorks reading 3D surface finishes defined in SOLIDWORKS to automate NC programming.

Figure 1. CAMWorks reuses defined 3D surface finishes to automate NC programming.

After machining, another example is inspection. Acting upon 3D geometric dimensioning and tolerancing (GD&T), CheckMate by Origin International can automatically program coordinate measuring machine (CMM) paths and soft gauges. Furthermore, CMM sample points or 3D-scanned point clouds can be overlaid and compared with the nominal CAD model. Then, CheckMate automatically generates a quality heat map per the semantic 3D GD&T as shown in Figure 2.

Figure 2. CheckMate automates the CMM programming and generates a quality heat map per 3D GD&T.

Along with these two examples in machining and inspection, model-based software-readable PMI can automate many other procedures such as cost analysis, quoting, process planning, robot programming, tolerance stack-up analysis and so on.

It’s important to note that none of these automations would matter if they didn’t bring tangible benefits. To prove the quantitative value metrics of MBD, the National Institute of Standards and Technology (NIST) in the United States conducted a study, Testing the Digital Thread in Support of Model-Based Manufacturing and Inspection.

The research team compared drawing-based and model-based approaches side by side in three steps: annotation, machining and inspection. It found that the model-based approach saved over 60 percent of the net hours across various practical test models as shown in Table 1. The time savings primarily came from the automations powered by the software-readable PMI.

2. MBD increases technical communication efficiencies

We all live in a 3D world and 3D is intuitive to us. When it comes to technical communications, we have to project 3D objects down to a 2D plane to author a drawing. Then, to interpret it, somebody else has to mentally reconstruct this 2D abstraction up to 3D again. This is a detour and it becomes excessive when you consider that most designs are built as 3D CAD models anyway.

This detour not only requires heavy mental coding and decoding, but also invites ambiguities. For example, look at the simple drawing in Figure 3. Is it a cut or an extrusion?

Figure 3. Ambiguity in a simple 2D drawing.

We don’t know, so we have to wait for clarifications, or find another view and correlate multiple perspectives to make a judgment. A simple drawing may be quick to figure out, but if we have to interpret a normal drawing such as in Figure 4, waiting, correlations and judgments are compounded substantially. This can make communication even harder and less efficient.

Figure 4. A normal drawing.

These issues impact business bottom lines enormously. For example, in the NIST study in Table 1, three simple and practical test models by Rockwell Collins were sent to two suppliers for machining and inspection. One took the model-based approach as an experiment and the other took the drawing-based approach as a controlled comparison.

The model-based supplier delivered parts in approximately five weeks, but the drawing-based supplier spent approximately eight months, or 27 weeks longer. The root cause was that the drawing-based supplier had to raise 12 questions related to interpreting the product definition from drawings, which led to work stoppages because the job had to be removed from the queue until clarifications were provided. In contrast, the model-based supplier asked no questions during its machining and inspection work.

Besides these focused studies, drawing communication issues become even more alarming in today’s manufacturing industry, which has grown exponentially more complicated. For example, a Boeing 787 Dreamliner contains about 2.3 million parts according to Jeff Plant with Boeing commercial airplanes. These are just final parts. Now let’s consider the engineering changes generated in the decades of product development and sustainment.

Regarding a similar aircraft, Bob Deragisch with Parker Aerospace pointed out that one change to a simple manifold created 1,700 changes to other related models and systems. The engineering change order (ECO) drawings would be 100 pages for this single change alone. If all the drawings of an airplane were printed, the package would be even bigger than the airplane, to which Deragisch declared “I can’t do that anymore with drawings!”

If a picture is worth 1,000 words, then a model is worth a million words because it’s in 3D and we can rotate and query it. The level of complexity in today’s manufacturing demands model-based communication to improve efficiency.

MBD provides a 3D presentation rather than a 2D abstraction. It minimizes the necessary mental coding and decoding and accordingly reduces miscommunication. In addition, dedicated MBD capabilities such as the cross-highlighting from a callout to its corresponding features provides an instant visual confirmation as shown in Figure 5.

Figure 5. Cross-highlighting from a 3D callout to corresponding features.

Many people believe that the majority of time saved with MBD comes from the avoidance of authoring a 2D drawing. It may indeed save time by not needing to create 2D drawing, but we need to create certain 3D callouts in models too. While 3D callouts may be faster than 2D callouts thanks to the feature-based 3D PMI automations as illustrated in a previous article, the real saving comes from the data consumption side, rather than the authoring side.

The reason is simple: The data, either in drawings or MBD, is created only once, but is consumed many times by many stakeholders. There are many consumption points across an organization and its supply chain, customer base and partner network throughout the entire product lifecycle, making consumption-side savings much larger than authoring-side savings.

3. MBD improves product quality

Much like model-based manufacturing automation, MBD can lead to significant quality improvements. Although the NIST report quoted the net hours and the total delivery time in a side-by-side comparison between drawing-based and model-based approaches, it turned out that time was not the full story. There were also major quality differences between drawing-based and model-based approaches. Figure 6 shows an unintended through-hole and a misshaped groove.

Figure 6. An unintended through-hole and a misshaped groove in the drawing-based part.

The unintended hole scrapped the entire part because there was no cost-effective way to fill it up and make it blind again. The root cause was that the drawing sent to the supplier missed a hole depth callout as shown in Figure 7.

Figure 7. The hole depth callout was missing in the drawing.

Without the depth, a hole defaults to a through-cut in drawings. How did this error slip through the cracks? By simply looking at the drawing in Figure 7, the machinist and even the inspector instinctively interpreted it as a through-cut. It didn’t even occur to them that this could be a blind one because there was no way to tell visually. As a comparison, the model-based supplier caught this issue because it used the model as the authority in numerical code (NC) programming.

In Figure 6, notice the surrounding seal groove on the drawing-based part on the right-hand side didn’t match the original design. This may not be a major issue, but does demonstrate another quality discrepancy due to the drawing-based approach. This type of issue prolongs the cycle time and erodes a manufacturer’s margin and can also compromise customer satisfaction.

Some may argue that these quality issues were the result of mismatching between 3D models and 2D drawings. If the drawings had matched the models perfectly, these issues would have been prevented.

Ideally, that would be true—but in reality, we all know that these discrepancies happen all the time. According to some manufacturers, up to 60 percent of 2D drawings don’t match 3D designs. The problem has more to do with years of drawings maintenance than initial creation. Shop floors could redline a paper drawing on the fly without notifying the design team, or a designer could update a 3D model but forget to update its drawings—especially in 2D PDF or paper formats. The link between models and drawings are broken, intentionally or unintentionally.

Rather than creating perfectly matched drawings separate from the models, why can’t we put them together? Why can’t we bypass drawings and put 3D PMI into models directly in one document?

4. MBD establishes manufacturing competitive advantages

For this reason, more and more organizations and manufacturers are moving toward the MBD approach. In the public sector, the Department of Defense (DoD) in the United States released the Military Standard 31000 revision A in 2013 to specifically define the requirements and best practices for its supply chain. In the private sector, General Electric (GE) named model-based manufacturing as one of the four pillars in its factory initiative, along with automation powered by sensors and the Industrial Internet of Things, process prototyping and informatics.

It isn’t just North America, either. The Japan Electronics and Information Technology Association, or JEITA, is the governing body of the Japan Industrial Standards (JIS), or equivalent of ASME standards in the U.S. In 2014, JEITA members paid special visits to manufacturers and software vendors across Europe and the U.S. to learn about MBD developments. A JIS standard for MBD is currently in the works.

These driving forces from the top of the global supply chain are generating strong ripple effects in the manufacturing industry. In order to be eligible in bids, stay competitive, win contracts and move up in the supplier tiers, manufacturers have to catch up and plan ahead. For example, Figure 8 shows growing percentages of SOLIDWORKS customers using or planning to use MBD. In many cases, small- to medium-sized machine shops have moved to MBD at the request of clients.

Figure 8. Growing percentages of SOLIDWORKS customers using or planning to use MBD (Survey sample sizes: 700 in 2009 and 524 in 2015).

5. MBD unleashes the power of emerging technologies

We are living in an exciting age for manufacturing. Emerging technologies, such as 3D printing, big data analysis, sensors, artificial intelligence and connected machines, are pushing manufacturing forward every day. There have been many initiatives around the globe, such as Industrial Internet of Things in the United States, Industry 4.0 in Germany and Made in China 2025.

MBD holds the potential to unleash the power of these emerging technologies and facilitate these initiatives. For example, 3D printing a part is very easy today with a 3D CAD model, but is unfeasible with 2D drawings. In addition, after printing, the part needs to be inspected according to its dimensioning and tolerancing requirements. Typically, these callouts are conveyed in 2D drawings. Since the design, printing and finished products are all in 3D already, it’s much more useful to avoid generating and maintaining a separate 2D drawing solely for inspection purposes by instead putting PMI directly into the 3D models.

Tolerance analysis is another example. Traditionally, all the tolerances are defined and locked in 2D drawings. Engineers have to visually read and manually re-enter the tolerances from drawings into a spreadsheet to calculate. But with the MBD approach, the digital semantic tolerances are liberated and analyzed by software applications automatically. Even better, the actual downstream as-built quality and cost data can be mined and correlated back with the upstream as-designed tolerances to optimize designs.

The GE “Brilliant” Factory initiative in Figure 9 illustrated them as the production feedback loop and the design feedback loop. The closed-loop analysis can reveal meaningful and actionable insights to cut costs while improving quality. The cost and quality goals may sound conflicting, but the reality is most tolerances are overly conservative. We all would love to loosen them to increase pass rates, but don’t necessarily have the clarity to pinpoint where to loosen without compromising the quality, so end up with tolerance overkills just to be safe. The closed-loop tolerance analysis powered by MBD can provide that much needed clarity.

Figure 9. The GE ”Brilliant” Factory initiative. (Image courtesy of Stephan Biller/Mfg4.)

Although these are the five biggest reasons to use MBD, there are also other benefits to consider, such as reduced paperwork, streamlined processes, workforce hiring/training and job satisfaction. To learn more about how SOLIDWORKS MBD can help you with your MBD implementations, please visit its product page.

About the Author

Oboe Wu is a SOLIDWORKS MBD product manager with 20 years of experience in engineering and software. He is an advocate of model-based enterprise (MBE) and smart manufacturing.  

Lions and mammoths encounter one another in a painting in Chauvet Cave, France. The painting was made between 28,000 and 30,000 years ago.

Drawings have been a staple of planning and recording since prehistory. In caves across the world, humans began drawing by marking their interaction with nature across the walls of their fire-lit homes. As human technology progressed, so did our ability to illustrate ideas.

Fast forwarding through the eons, drawing took on many forms. Perspective was first honed by the Greeks, the Romans brought precision to the drafting table and the Middle Ages brought skewed perspectives with oblique visual descriptions of cities, castles and wars. Though drafting would progress, it wasn’t until the Renaissance that technical drawing came into its own. Working in Florence, Italy, a designer named Filippo Brunelleschi ushered in a new theory of drawing that contemporary people would understand as a blueprint. Using linear perspective, the Italian began constructing some of the most wonderful architectural feats that world had ever seen. To guide their construction, Filippo used his diagrams and, in doing so, introduced the world to technical drawings.

Since their invention, technical drawings have evolved. In the late 18th century, Gaspard Monge, a French mathematician, developed his ideas of descriptive geometry, codifying the planar views that manufacturers are familiar with today. In the middle of the 20th century, another seismic development occurred in technical drawing. Geometric dimensioning and tolerancing (GD&T) was created to make manufactured goods more consistent with their technical specifications by more precisely defining required precision and allowable variability.

Most recently, the technical drawing’s path has merged with another transcendent technology—the computer. Since the mid-1970s, technical drawing has moved off of the drafting table and onto the computer screen. Today, designers use CAD to create 2D drawings, 3D models and animations that describe how parts should be made. With CAD, technical drawings have become easier to create and share. However, engineers have started to realize that CAD drawings aren’t necessarily the best way to distribute, correct or archive manufacturing documents. Instead of relying on drawings, engineers have started to look for ways to combine the models they’re creating with the technical drawings that were based on those 2D and 3D forms. This new phase of technical drafting has been called model-based definition (MBD).

What Is MBD?

MBD is essentially a term that describes a 3D model that contains all of the annotation data that would be needed for a part to be manufactured. Aside from dimensions, an MBD model will communicate a component’s GD&T requirements, material information, configuration details, and other data that could be useful for anyone that might have input into the manufacturing of a design.

An MBD 3D model. (Image courtesy of Quality Digest.)

Who’s Using MBD?

As of now, MBD is still a nascent technical drawing paradigm. However, industrial catalysts like the U.S. Department of Defense (DoD), select companies in the aerospace industry and the automotive sector have started to insist that any vendors working on affiliated projects have to produce 3D MBD models.

One of the biggest factors driving this trend is the lifespan that some DoD and aerospace products see before they’re eventually retired. For the DoD or Boeing, having a machine run for 20, 30 or even 50 years isn’t out of the ordinary. With service lives that stretch out that long, its easy to see that building design information directly into a model can be invaluable. Who’s to say that the designer of a particular system on a legacy aircraft will be around to impart his or her design intent to the younger engineers deputizing the design work when something goes wrong down the road?

Another benefit that MBD offers engineers is the ability to use their models as a verification datum upon which they can automate inspection of manufactured parts. With all of its dimension and definitions built right into the model, MBD components can be used in conjunction with coordinate measuring machines and 3D scanners to ensure that a part meets documented manufacturing standards without having to reference outside drawings. All of the information that would be needed to compare the two parts would be right there attached to the model, making an often painstaking and time-consuming process much easier and quicker, while also enabling more process automation.

Aside from its communication and validation benefits, MBD has also been able to deliver cost-savings to those who have adopted the emerging documentation trend. Since adopting MBD principles, Toyota, Boeing and BAE have demonstrated up to a 50 percent reduction in costs in the product development processes. What’s more, the Naval Air Warfare Center Aircraft Division based in Lakehurst, N.J., has noted that after implementing MBD into its design workflow, the cost of labor used in component fabrication has dropped 30 percent.

Why Adopt MBD?

In the end, MBD is valuable because it preserves the geometry of a 3D model while still delivering all of its manufacturing information that’s usually associated with a 2D technical drawing. Because MBD relies on 3D geometry, it gives manufacturers or anyone interacting with a 3D model greater insight into the design intent of each feature as well as a more natural way to interact with a virtual part. Though that might seem simplistic in its promise, machinists who have to transform raw stock into goods could really benefit from visualizing a part in 3D before deciding on CAM setups and toolpaths.

Furthermore, design teams working across time zones could use MBD models to better understand their colleagues’ design requirements without having to sift through reams of paper drawings and manually searching for minute bits of information.

Finally, as we’ve seen, drawings have been evolving ever since man wanted to communicate an idea down through the ages. While MBD, with its 3D nature and its intrinsic link to computers, might seem completely disconnected from the cave paintings of old, when you take a step back, you notice that both techniques are trying to do the same thing—communicate an idea in the most sophisticated and enduring way possible so that good ideas find fewer ways to be lost.

If MBD is going to be the next evolution in drawing’s long history, the age-old trade could have done worse. With its ability to condense information into an encyclopedic form, MBD appears to be an excellent way forward for technical drawing.

About the Author

Kyle Maxey is a mechanical designer and writer from Austin, TX. He earned a degree in Film at Bard College and has since studied Mechanical and Architectural drafting at Austin Community College. As a designer Kyle has had vast experience with CAD software and rapid prototyping. One day he dreams of becoming a toy designer.