We introduced the proven 3D geometric dimensioning and tolerancing (GD&T) advantages over 2D drawings at Johnson Controls in a previous article. Here are several examples where 3D GD&T in CATIA V5 can help:
- Organizes datum symbols and feature control frames in a structured tree for easier lookups
- Cross-highlights from 3D GD&T in the tree to corresponding model features in the graphics area
- Recognizes separate datum targets as one cohesive datum feature
- Flags GD&T errors automatically
- Guides proper GD&T definitions by providing only valid options according to the selected features
Let’s continue in this article with the solid benefits brought by model-based definition (MBD) and practical implementation suggestions.
According to Ram Pentakota, the engineering director with the Johnson Controls automotive seating division, quantitative benefits have been observed across multiple production procedures, such as design, engineering, manufacturing, quoting, quality and risk management. Table 1 summarizes the benefit categories, improvement range and key enablers.
Table 1. MBD benefits observed at Johnson Controls.
|Benefit Category||Improvement Range||Key Enablers|
|Designer efficiency||10%–30%||GD&T advisor in CATIA V5,which improves the GD&T annotations added to the 3D models|
|Engineering efficiency||5%–10%||Better GD&T annotations, which reduces engineering’s involvement in repetitive drawing iterations due to the traditional GD&T checking and validations|
|Engineering effectiveness||10%–20%||Productivity gains due to the unambiguous and high-quality GD&T annotations|
|Reduced the need of checking the manufactured parts||15%–25%||Access to the correct GD&T annotations for the manufacturing process planning|
|Reduced there work and scrap||10%–20%||Access to the unambiguous and robust product information|
|Reduced the cost of quality||2%–10 %||Access to the correct GD&T annotations for the manufacturing process planning|
|Improved the win rate and margins through higher quote confidence||To be determined||Sufficient time for the cost estimation and sourcing based on the timely and accurate product and manufacturing (PMI) data|
|Quality throughout the product lifecycle||Intangible but significant||Reduction of the error-prone but non–value-added work|
|Risk mitigations against significant product fulfillment errors||Significant||The single source of product information in 3D, which avoids the traditional inconsistencies between 3D models and 2D drawings.
Access to correct product information to all stakeholders
The benefits are certainly attractive, but the key question is how other manufacturers can copy the success. Let’s look into several recommended practices.
First of all, for many businesses, the transition from 2D drawings to MBD seems to be too big a leap to accomplish today. For instance, to comply with legal or governmental regulatory requirements, companies oftentimes still need to submit 2D drawing documents. Also, at the work site, the field team members need to see the whole drawing at once and mark up comments quickly. 2D drawing printouts come in very handy in these cases, and they don’t need digital equipment onsite at all.
To serve these needs and facilitate the transition, Johnson Controls developed an interim approach. The team developed tools to generate 2D drawings automatically with typical view layouts according to the 3D MBD data. At a first glance, this may seem to be a step away from MBD, but it’s actually a strategic bridge towards an effective enabler for MBD.
The reality is that 2D drawings are not going away anytime soon. There are many operations that have always been done in 2D and will continue in 2D for many years, for conventional, regulatory or pragmatic reasons. We can’t just jump off the cliff and start everything from scratch.
The interim automatic 2D drawing approach can help shift the orientation and effort from 2D drawings to 3D MBD. Designers and engineers can now gradually start defining product marketing information(PMI) and creating views in 3D besides modeling. Just in case 2D drawings are needed, with the work already done in 3D, 2D drawings can be generated quickly at little effort. The net result is that the focus can be gradually shifted toward MBD.
Johnson Controls is not the only manufacturer who came up with this transition strategy. According to Prashant Kulkarni with GE Power and Water, on-demand paper drawing was implemented in GE’s MBD process too. Figure 1 shows an on-demand drawing report dialog box, where notes, views, tables and signatures can be selected from the existing MBD datasets.
Then the 3D MBD information will be passed along to a drawing template to generate drawings automatically as shown in Figure 2.
Kulkarni called these “pseudo-drawings,” in that they are not created through traditional 2D detailing. Most of the work is actually done in 3D, and the pseudo-drawings are just a quick report of the MBD data. These drawings can be printed out as hard copies as needed, but they must respect the 3D data as the single source of truth, instead of the other way around. You can learn more details about GE’s transitional approach in a previous blog post, “Drawingless or Paperless?”
SOLIDWORKS MBD provides similar capabilities for reusing MBD data in 2D drawings. For instance, Figure 3 shows a 3D model with attached PMI in its front view.
On a 2D drawing sheet, you can choose to import annotations from the 3D model as shown in Figure 4. As you drag and drop the front view from the view palette to the sheet, the DimXpert PMI will be automatically carried over from the model to the drawing. This annotation import automation can save effort in the 2D drawing creation and help steer more energy towards 3D.
In this article, we summarized the solid benefits observed at Johnson Controls. Then we looked at a common challenge facing manufacturers today: how to manage the transition from 2D drawings to MBD. As a strategic bridge and effective enabler, an automatic 2D drawing approach based on the MBD data has been adopted by both Johnson Controls and GE Power and Water. Lastly, we introduced a SOLIDWORKS function to reuse 3D annotations in 2D drawings in the direction of the above discussion. 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 product manager with 20 years of experience in engineering and software. He is an advocate of model-based enterprise and smart manufacturing.