How do I phrase "remote work" better?

Solution 1:

Remote is fine, but the relationship between on-site work and remote work and "the period SomeTimePeriod" is not clear. Does SomeTimePeriod refer to the remote working, or to the entire period of assistance? I'll assume it's the entire period.

The report summarizes the consultant's technical assistance to the Statistical Agency of Kosovo, both in on-site missions and remotely, during the period SomeTimePeriod.

Or, if it's obvious that being in Kosovo is not your father's normal location, and he would have had to have travelled there,

The report summarizes the consultant's technical assistance to the Statistical Agency of Kosovo, both on-site and remotely, during the period SomeTimePeriod.

You could make that more explicit:

The report summarizes the consultant's technical assistance to the Statistical Agency of Kosovo, both on-site and remotely from Location, during the period SomeTimePeriod.

Solution 2:

The established term telecommute, "To work from home, sometimes for part of a working day or week, using a computer connected to one's employer's network or via the Internet", perhaps is appropriate, but more probably is over-specialized for your purpose. One could refer to offsite work, but that is little better than remote work, leaving the ambiguity of remote from what, offsite from what. Perhaps replace "...and remote work during..." with "...and work (in Armenia) during..." or "...and work (back in Armenia) during...", or substitute the name of a city, organization, or building in place of the country name.