People of some occupations usually do their work at the specifically equipped facilities. For example, you go to the barbershop to get a haircut or you go to the dentist, when you have a tooth pain.
At some occasions, however, these professionals could arrange the service on your site (at your home, for example).
What's this kind of service / action called?
UPDATE: I am researching this particularly for barbers and have found "on-demand" term being used for this service.
Barbers are available on-demand or you can schedule up to a week in advance
My second question is, whether "on-demand" is commonly in use for the barbers? If so, what other occupations it might be used for?