Why the Best Designs Start with Simulation

Written By: Tiffany Bailey
  • 1/18/2018

3D CAD has become so easy to use that almost anyone with a good eye can make great-looking designs—especially with modern rendering capabilities that add realistic-looking materials and strategically positioned lights to the model.

But no matter how good those race cars and robots look, if they don’t have good data behind them, they may not get past prototyping. In fact, they may not even be buildable.

That’s why most product developers do more than design. They engineer. Using equations and simulation tools, they determine up front what will work under real-world conditions and what won’t.

At least that’s the opinion of our in house Simulation expert, Greg Brown. We asked him to tell us more about why he thinks good product design starts and ends with simulation. 

Q: You seem to be suggesting that not all who design are engineering.

A: That’s true. Especially new 3D CAD users who often find themselves tempted to focus on shape. They become very good at copying existing designs. Replicating things that they see. That’s great, and 3D CAD makes it easy for them to do that.

However, they won’t know whether their design will work unless they analyze it. They’re drawing a solution before they’ve learned the fundamentals of what the finished product is supposed to be doing.

Q: And that’s where “engineering” comes in?

A: Yes. If you’re developing a real-world product, you should understand what your model (and the manufactured object) is doing at a fundamental level. Engineers make a lot of decisions throughout the 3D modeling process. For example, they decide what the thickness should be, whether there should be a fillet radius or support ribs, etc.

They can’t make those decisions based on their gut. They need hard data or a fundamental understanding of the design. Otherwise, they run into difficult and time consuming changes to those initial design decisions.

Q: So how do engineers find this fundamental data?

A: Simulation. But note that I define that term broadly. It is not just Finite Element Analysis (FEA) or computational fluid dynamics (CFD) of the final product. It could also be early analysis based on a simple idea and a couple equations. In my mind, those initial calculations are still simulation. And, they can play an integral part in the engineering process. That’s why I’m a big fan of PTC Mathcad for calculating, capturing, and documenting equations that you’ll build the model around.

Q: Are you proposing that engineers start simulation before they build geometry.

A: Yes. Before 3D CAD was common, engineers simplified a model to understand the fundamentals of what the design should achieve. From there, the actual geometry followed.

That traditional thinking can still benefit modern developers. After all, if you want to perform quality simulations, you need to have a good grasp of the fundamentals. You can’t just create geometry, stick the geometry in an assembly, and then hope for the best. 

Q: What about engineers who work with professional analysts? Do they need to perform their own simulations early too?

A: For years, product developers designed their models and sent them to analysts to evaluate. Many still do. However, even in those situations, engineers can perform some fundamental calculations throughout the design process to ensure they’re handing off a quality design to the analyst. This fundamental work benefits everyone and saves iterations and time between design and analysis.

Q: Do simulation tools and skills change over time?

A: Simulation tools do change over time. Basically, the tools add more physics and more capabilities to physical situations. For example, better contact, more materials, bigger models, and even co-simulation.

Simulation of a mechanism in Creo Simulate.


These new tools are wonderful. But, again, it still helps to understand the essentials. If engineers don’t understand the fundamentals, then bigger, faster tools really just get us to strange results and errors faster.

Q: What if I just skip the extra steps and go ahead and design my cool idea for a stand up desk. I think I can get a manufacturer in my neighborhood to build it.

A: There’s a level of uncertainty. You might get away with it and your model might work. Or, you might be right on the edge of disaster.

 Additionally, you’re not learning as much as you could about your design and your design approach. That kind of knowledge can benefit not only your current project, but also future design work. 

Analyzing your design choices tells you what works and doesn’t work with this model and also with your future models.

Give Your Engineers the Tools They Need

Want to learn more about how to make simulation work for you and your team? Download the infographic to learn the Top 5 Best Practices for empowering design engineers. And get started realizing the potential of simulation: fantastic products.

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About the Author

Tiffany Bailey

Tiffany Bailey is a content writer and editor for PTC. She has more than a decade of experience as a technical writer/editor. And over 5 years of experience writing about mechanical engineering, 3D CAD, and PDM. Her work spans topics like data migration and management, IoT and big data, IT security, additive manufacturing, simulation, and SaaS. She especially enjoys interviewing customers, product managers, and thought leaders to uncover new ideas and innovations.