Synchronous Technology: What is it, Really?

Synchronous Technology is the name Siemens has given to their direct modeling technology.  Available in both NX and Solid Edge, the product can operate in either history or history-free modeling modes, and can also perform parametric or direct modeling operations.  For this post, I will be writing about Synchronous in NX, though much of it applies to Solid Edge.

Until NX9, this technology was limited to 3D modeling operations.  Now, Siemens has added edges and 2D Sketch geometry to Synchronous!  I will post about 2D Synchronous next week; today we will focus on Synchronous for 3D modeling.

Today, the mechanical CAD industry is dominated by history-based parametric solid modeling.History-based parametric modeling is powerful, in that engineers can specify their models in complex mathematical terms, capturing their design intent while doing so.

The initial authoring of a model is typically known as “forward create”, and is often done by one person or, for very complex models, a small team.  While building a model, we find it fairly easy to express intent and make changes.

But what happens when the original modeling strategy is forgotten, or the model must pass through a translator where all of the parametric data is lost? 


Many CAD users find it very difficult and time-consuming to figure out how to make edits to parametric models, often requiring time to step through the model, essentially reverse engineering what the original author was thinking.

This chart shows four basic choices:


As you can see, history-based modeling can be done either direct, or parametrically, or BOTH!

This frees the user to either ignore the model history and perform an edit directly, or to employ the model history and/or both to accomplish a design change.

It’s important to note that models do not need to be native in order to take best advantage of Synchronous Technology.  Both 2D and 3D non-native geometry, such as DXF, DWG, STEP, and IGES, as well as 3D model information from other CAD systems like Solidworks and Inventor, can be imported into NX9 and manipulated with Synchronous Technology as if it were native to the system.  (CATIA and Pro/e models can be manipulated as well, however there is an additional fee for those translators.)


In the parametric mode, design intent is captured as part of the modeling process and it remains a part of the model.  This requires a native data representation that gets lost when the model passes between CAD systems.

What’s so cool about Synchronous is that it figures out the design intent at the time of the operation.  If it’s history-based direct modeling, it remembers it for subsequent parameter changes later on, just like history-based modeling operations do.  This means, among other things, that “dumb” imported solid models can be parameterized just as if they were native models. 

Now, if it’s history-free direct modeling, the design intent captured is transitory and can be ignored after its useful purpose at the time has passed.  This means that rapidly changing models can be changed with a far lower overhead than is typical of parametric-only systems with fewer overall workflow choices for the user.


Synchronous “parses” the geometry in an attempt to see it as we do; lines connected, symmetry, tangency, etc. are sorted out as the operation is happening.  You can quickly adjust what NX finds, complete the operation, and move on in a way that is leaner than typically possible using parametric modeling techniques.

This is accomplished with on-screen modifiers that enable the user to very quickly arrive at the right intent for their purpose.  Things like ribs, pockets, bosses, patterns of holes, blends, and other similar features can be quickly selected via the intent engine built into Synchronous, avoiding laborious face-by-face picking normally needed to make these kinds of changes in direct modeling systems.

In this way, you are free to focus on the geometry particulars and how they align with design requirements.

Now, what about you?  Have you tried Synchronous yet?  What did you think?  If you have any questions, or need assistance incorporating Synchronous into your workflow, please don’t hesitate to let us know.

Thanks for reading.

Solid Edge