If a customer wants to order 100 items (bulk order) at a time is it possible to process this order in bpel order processing.(for example 100 mobile phones through on line)
and only one po.xml is enough?
You can read 1 po file, with 100 orders, and send them to a target system (EBS for example, using API).
So, for that example you can call the API 100 times. Or a better solution, is to create a procedure that will get a table of records with all the data, and within it call the API.
According to your requirements, you can also create a sub process that will get 1 PO and call the target system. In the parent process (the one that polls the file) you will run the loop 100 times and call the sub process.