What proxies or assumptions in a transaction can be used to determine the place of supply?

The various element involved in a transaction in
services can be used as proxies to determine the place
of supply. An assumption or proxy which gives more
appropriate result than others for determining the place of
supply, could be used for determining the place of supply.
The same are discussed below:
(a) location of service provider;
(b) the location of service receiver;
(c) the place where the activity takes place/ place
of performance;
(d) the place where it is consumed; and
(e) the place/person to which actual benefit flows