How to Open an Assembly without all the Parts

Unable to locate fileMany times you will find yourself in the unfortunate situation where you open a SOLIDWORKS assembly and you are immediately greeted by this message alerting you that SOLIDWORKS can’t find some or all of the components in the assembly. Selecting the option to manually browse for the component yourself is actually step 13 in a very complex search routine used by SOLIDWORKS to find components referenced by the assembly. There are a number of reasons for this message: maybe the file was renamed, moved, or perhaps even deleted.

In this post, we’re going to assume you didn’t move, delete, or rename the file; it is written under the premise that you never even had the files in the first place. This happens all the time when you receive an assembly from someone who didn’t use the collaborative ease of “Pack and Go” to package everything SOLIDWORKS will need so you can work with the files. As a result, you get just an assembly file and not a single part file. I’m sure we’ve all been there, but did you know that not all is lost. You can still open up the assembly file using “Large Design Review.”

Large Design Review

Large Design Review (LDR) was added to SOLIDWORKS in 2012 as a tool designed to enable you to quickly open and view very large assemblies. With LDR, you can’t edit a part or assembly but you can take measurements, create section views, and even walk-through animations. Although it was created to be used to easily view massive assemblies, it can also be used to view smaller assemblies that you previously were unable to open and view without this tool.

Let’s see how this is possible by taking a close look at SOLIDWORKS files and their data structure.  Pop open the hood of a SOLIDWORKS file and you will find three chunks of data: Parasolid, Tessellation, and Parametric.

  1. Parasolid: This portion is generated by the modeling kernel. Think of it as a database containing the mathematical definition of your model-its topology (trimmed surfaces, loops, edges, vertices, etc.).
  2. Tessellation: This is the triangle information or the visualization data used to generate what you see in the graphics area. Why triangles you ask? It’s because any 3D object can be approximated by fitting together triangles. Learn more about this by watching this great YouTube video from Computerphile.
  3. Parameteric: Think of this as a step by step instruction set used by SOLIDWORKS to build your model (AKA the FeatureManager design tree).

whats in a swx file

Opening Modes


When you open a SOLIDWORKS file, you have the option to open it in a variety of different ways or modes such as resolved, lightweight, large assembly mode, speedpak and large design review. As you can see in the image, with these different modes you are essentially choosing which portion of data you wish to load. This is why LDR allows you to open an assembly file without all the referenced parts. LDR opens SOLIDWORKS files by loading only the tessellation data which is just the graphical portion of the assembly.


Pick the mode you want and get the data you need.

Without the Parasolid and Parametric data you cannot edit the assembly, but if all you want is to simply open and view the assembly file–the Tessellation data is all you need. In other words, you can open and view an assembly of any size with or without the referenced components using Large Design Review. To me, the something on the right is much better than the nothing on the left.

:-( Missing Components :-) There's the assembly!


Check out this video which walks you through this great functionality.

Written by Stephen Petrock. Stephen is a SOLIDWORKS Elite Application Engineer working for ModernTech out of their South Florida office in Fort Lauderdale.






Stephen Petrock
Since 1998, TriMech has helped our clients design better products by partnering with them and offering, not only CAD, CAE, PDM, FEA, CAM software products, but also by engineering solutions involving full-time and temporary staffing, contract design, analysis and drafting services, rapid prototyping, custom programming and implementation services. TriMech is a value-added reseller of SOLIDWORKS and Stratasys 3D Printers in the Mid-Atlantic and South-East including New Jersey, Pennsylvania, Delaware, Maryland, West Virginia, Virginia, North Carolina, South Carolina, Tennessee, South Carolina, Georgia, Florida, Alabama, Mississippi, Oklahoma, Arkansas and Louisiana.
Stephen Petrock