3D CAD Model Gear

Chad Jackson

Siemens PLM and Synchronous Technology in Solid Edge

March 28, 2011

There certainly has been a lot going on in the CAD industry of late. It seems as if just about everyone has been talking about adding or integrating direct modeling into what they offer. Thinking back, direct modeling and feature-history modeling have both been around for some time. But the first software provider to really …

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3D CAD Model Gear

Siemens PLM and Synchronous Technology in Solid Edge

There certainly has been a lot going on in the CAD industry of late. It seems as if just about everyone has been talking about adding or integrating direct modeling into what they offer. Thinking back, direct modeling and feature-history modeling have both been around for some time. But the first software provider to really try to integrate the two together was Siemens PLM when they launched Synchronous Technology. But since then, everyone’s caught up to what Siemens PLM did, right? After some investigation, I think there are several capabilities that are still unique.


Back in April 2008, Siemens PLM announced it had developed Synchronous Technology and was integrating it into both of their CAD applications, NX and Solid Edge (press release). Then in October 2010, Siemens launched the third version of Synchronous Technology, dubbed ST3 (press release).

Capabilities Provided

So just what does Synchronous Technology do? To answer that question, it’s important to understand how it is different. And it all has to do with how the geometry of the model is generated. So let’s look at other methods of generating geometry first.

What Does Synchronous Technology Do?

Back in December, I described two different modeling paradigms, the feature-history modeling paradigm and the explicit modeling paradigm, in a post titled A MCAD Modeling Term and Definition Framework.

  • In essence, the feature-history modeling paradigm generates geometry by calculating (or recalculating if there is a change) a number of features or operations in a specific order. If there are no interdependencies between features, they could be calculated simultaneously and some CAD applications handle them that way. However, many CAD applications simply recalculate all features that occur after the one that was edited.
  • In the explicit modeling paradigm, there really is no recipe that is remembered in how the geometry is generated. Only the geometric definition itself is remembered. That definition can be changed by geometric operations like move, rotate, etc.

With all that said, what does Synchronous Technology do? To start, the operations to build model geometry is remembered. So in that way it is somewhat similar to the feature-history modeling paradigm. But instead of solving in a specific order as it is done in the feature-history modeling paradigm, with Synchronous Technology the geometry operations relevant to the change at hand are solved simultaneously. It’s a subtle distinction that might be hard to grasp at first. But its actually very important. In the feature-history paradigm, you change a single feature and then see that change propagate down the set of features or operations in order. With Synchronous Technology, as you change some geometry, only the operations directly related to the edit are solved simultaneous and dynamically in real-time.

How Does Synchronous Technology Show Up in Solid Edge?

I recently had a long conversation with Dan Staples of Siemens PLM about ST. And what he said about the beginnings of the technology were interesting. Basically, when it was first launched, they thought they would keep the synchronous mode of modeling and the existing feature-history based mode of modeling separate from one another. They seemed like two very different ways of building geometry. But over time, their customers increasingly demanded the ability to switch back and forth between these two modes. And that set the vision behind the latest capabilities that are part of the 3rd version of ST. With that release, they made it possible to combine the two means of building geometry.

So now, in Solid Edge, you basically see two areas in the model tree. In the synchronous area of the model tree, you have this ability to create and manipulate geometry in the simultaneous fashion described above. But the other area in the model tree let’s you specify an order to the geometry features. And as you would expect, those geometric features are calculated or solved in the order in which they appear.

Analysis and Commentary

With a little understanding of what ST is and how it works, you have to ask yourself a question: what’s it mean? But there’s another interesting question: how’s it related to direct modeling?

If you take a quick look back at the post A MCAD Modeling Term and Definition Framework again, you’ll see that the direct modeling paradigm allows you to directly manipulate geometry with push, pull, drag or even parametric types of interactions. Often direct modeling techniques are applied to models with explicit geometry definitions. Those models don’t have a recipe of geometric operations that is remembered. And as a result, as geometry is moved, twisted, removed or otherwise, you don’t have features or geometric operations failing. Of course, these same types of techniques can also be applied to models built up in the feature-history paradigm but the changes that users can make are often constrained by the feature definitions themselves. You can’t turn an extrusion into a revolution… and if you try interesting and undesireable things might happen.

But that’s where ST and direct modeling have a profoundly different interaction than what you see elsewhere in other CAD applications. As you directly manipulate a model, ST behind the scenes is simultaneously solving all of the remembered geometric operations. Essentially the entire model is being recalculated on the fly in real-time. As a result, that can enable some potential changes you might not be able to get to with the feature-history paradigm, because you might run into failures, or with the explicit modeling paradigm, because geometric operations aren’t remembered. In summary, it can enable powerful changes.

But another point that is important is who is going to use ST. During my conversation with Dan Staples of Siemens PLM, he restated what he said on the Cadalyst OTE CAD Smackdown discussion (audio replay): they are trying to enable the CAD Specialist or Designer, not everyone under the sun. I understand the positioning of the technology. And I think it’s powerful. However, as I’ve written before in a post titled The Subtle Distinction Between Designing and Documenting Products, I think direct and 2D modeling has the potential to address the needs of underserved engineers. And in particular, ST seems to offer very powerful capabilities unique in the industry. But Siemens PLM is focused on their task at hand. As many other software providers have seen before, there are many dangers in trying to boil the ocean.

Summary and Questions

In summary, Synchronous Technology offers a new way to calculating model geometry that offers some significant advantages when paired with direct modeling paradigms. Siemens PLM is highly focused on using it to super-enable CAD Specialists and Designers and not enabling the jobs of other roles in the organization like engineers. I think it offers unique capabilities that are worth exploring.

Now it’s your turn to weigh in. For those that are using ST3, can you share some perspectives on how this technology is different from what you have used in the past? What makes it powerful? Alternatively, have there been any difficulties in getting adjusted to ST3? Sound off and let us know what you think.

Take care. Talk soon. And thanks for reading.

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