Collate IDocs from a vendor

Hi friends,

I am using SAP 7.1. I have a scenario where the PO is sent from ECC to File. The interface is triggered hourly and both header and line items pass through it. We are using SFTP at the target. We have a requirement where the IDocs from the same vendor should be collated. If six IDocs come in an hour and if  five pertains to the prticular IDoc then we need to collect all the five Idocs and then the mapping should work for the sixth IDoc.

Is it possible?

Regards

Harish