What Is Model Based Definition? [Interview with Jennifer Herron]

Written by: Cat McClintock

When you look at a 3D model, you can see the shape of a product, but you often don’t know all the engineering details required to successfully manufacture the real-world version. To get the complete picture, you need dimensions, surface finish, materials, tolerances, and more.

Traditionally, that non-geometric information appears in separate 2D drawings or documents. Engineers develop the product as a 3D model, and then add the product manufacturing information (PMI), as annotations on those drawings.

But what happens when the model is complex and downstream processes, vendors, partners, etc., can’t easily discern the geometry or annotations? Or when the model is updated and all those drawings need to be updated? This problem isn’t unusual, and leads to a lot of waste.

That’s the problem that model based definition (MBD) seeks to solve.

A 3D model with annotations

It’s easier to see annotation references on a model than it is to see them on a drawing.

We recently talked to Jennifer Herron, the founder and CEO of Action Engineering and author of the book Re-Use Your CAD: The Model-Based CAD Handbook about MBD. She clarified some of the confusing jargon you see around MBD—model based enterprise, model based design, model based engineering, etc.

In the simplest terms, model-based definition is an annotated model and its associated data elements that define a product, which can be used effectively without a drawing. The model is the source authority that drives all engineering activities. It is used downstream, by suppliers, and across organizations within an enterprise.

Look at this video to learn more:

The biggest benefit with MBD, says Herron, is increased communication throughout the enterprise, which benefits everyone downstream, such as manufacturing and quality. It’s easier find and understand annotation, geometry, and design intent on a model than it is on a drawing.

Get more from your models

Engineers are discovering the benefits of MBD outweigh any challenges. Plus, hurdles to creating a single source authority model for every stage of product development are falling away as more teams implement an MBD approach.

To learn more about model-based definition, check out the free e-book from PTC. You’ll find out more about the limits of 2D drawings, how MBD simplifies complexity, and where to get started. Download your copy today.

 Download the MBD eBook

Tags: CAD Retail and Consumer Products Connected Devices

About the Author

Cat McClintock

Cat McClintock edits the Creo and Mathcad blogs for PTC.  She has been a writer and editor for 15+ years,  working for CAD, PDM, ERP, and CRM software companies. Prior to that, she edited science journals for an academic publisher and aligned optical assemblies for a medical device manufacturer. She holds degrees in Technical Journalism, Classics, and Electro-Optics. She loves talking to PTC customers and learning about the interesting work they're doing and the innovative ways they use the software.