Conversion from PAR to Navisworks is not supported yet :(

PAR is a CAD format that generates 3D object layouts. Solid Edge, a 3D CAD system from Siemens Digital Industries Software, uses the .par extension for its part files, including their geometric forms, appearance, and structural elements.

The PAR file can be combined with other Solid Edge parts to a single assembly (ASM file).

Navisworks is a native file of Navisworks® project review software by Autodesk.

Navisworks files come in three formats: NWD, NWF, and NWC. An NWD is a single file that contains all model geometry, environment, viewpoints, and review markups. An NWF file is a list of links to the original files. It doesn't keep model geometry and, to be opened, requires access to the original CAD files. An NWC is a cache file created from any native CAD or laser scan files, when opened in Navisworks.