Simon Moreau has shared a nice addin for Navisworks that allows the automatic grouping of clashes. From his blog:
"This plug-in enables a lot of possibilities for sorting clash detection results in a meaningful report, and will become a full-time member of my coordination toolbox.

To install this plug-in, you can copy-paste the ClashDetective.ADSK.dll file available here in a new ClashDetective.ADSK folder in C:\Program Files\Autodesk\Navisworks Manage 2016\Plugins. You can also see my edited version of the example code here."


Original post: Grouping clash results | BIM 42
Heads-up from Michael Clothier

Here is what the installation folder looks like:

And the addin ribbon in Navisworks Manage 2016:


You can also download the Navisworks SDK from here:

Navisworks 2016 SDK (Updated April 7th) (exe - 207 Mb)
Navisworks 2015 SDK (Updated July 1st) (exe - 193 Mb)
Navisworks 2014 SDK (exe - 217 Mb)


Click here to view the entire blog post.