*.obf and *.pbf are compressed binary file extensions of OSM data.
I want to open these in GIS software like ArcGIS.
How is the conversion possible?
Is there any automated tool?
SpatiaLite now supports opening ProtoBuf encoded OSM files (via the new readosm library). You can use that to import the files into SpatiaLite tools and then you can use tools like QGIS to do any work required. See the documentation for SpatiaLite OSM tools for specific details on the import and which tools to use for what purpose.
I tried using GDAL, but this is difficult for non-programmers.
This option is way more efficient and easy: http://wiki.openstreetmap.org/wiki/Osmconvert
You can convert the file to an .osm, which can be opened through the ArcGIS for OSM tool. You get a large file though (file size x 20).