In what situations we have to choose Call transition, Session method, LSMW

Hi,

In Batch Data Communication we have 3 methods

1) Call Transaction Method,       2) Session Method,      3) LSMW.

I am aware of the above 3 methods. But I am not clear in what situations we have to choose Call transition, in what situations we have to choose Session method, similarly in what situations we have to choose LSMW.

Can any body please explain?

Thanks in advance.

Ramana