I assume that you are talking about pushing the document from TN to IS. Whenever you send any document to TN, TN rules perform specific function with that document, in your case it will be routed to any specific service in IS.
You should never have Save piple(to File) in production. So I would recommend to just take that step off.
Now to the main point, if you are sending multiple document to TN they will be processed seperately and you don’t have to do any extra thing for that but if you are sending one large XML document to TN then you have to split that in your service which will be called by TN rule or have a gateway service to split the document before sending it to TN.
HTH
#B2B-Integration#webMethods#Integration-Server-and-ESB