Is it possible to do service area analysis using offline resources? Perhaps using Local Server?
Once you create geoprocessing package (.gpk) for the service area in ArcMap/Pro, you can consume it through LocalGeoprocessingService in runtime application.
The next release (v100.2) will support this without local server.
Any hints on how soon will that be? End of year? Dev Summit 2018?
We're shooting for end of year (with the normal caveats of things can always change)