Document split by profit center

Hi,

We are in a re-implementation scenario.Client is using the older version of SAP and the new version is ECC 6.0.The requirement is to activate the document splitting with profit center and segment as scenarios.(Charecteristics for splitting).As on the cutoff date we take the balances and upload the same in the ECC 6.0 system.The question is how these balances will split.How the customer and vendor line items will split.

Please clarify...let me know if you need further info.

Thanks