Intercompany sales during SAP Hana S/4 migration

[apoorvas]

Dear Experts,

Our company is in the midst of migration to SAP Hana S/4 from ECC 6.0

We are operating in all European countries and  the migration is planned in phases/waves. Current scenario we have multiple company codes and plants in all EU locations running on a single instance of ECC 6

so my question is if we are selling from say Belgium with the delivering plant in France( current scenario) and in the first phase only Belgium CoCode will be migrated to S/4, how do we manages sales with the delivering plant being in France( on old ECC system) not being visible to Belgium Sales Area ( on the new S/4 system)?

This is only one scenario and the reverse situation will also occur with sales from France Sales org( on ECC) being delivered from Belgium plant ( on S/4) 

So we will have two system running in parallel during transition, with no stock visibility between each other, how can this be managed ? 

Please if anyone has been in this situation can share how it was managed ?

Thank you for your responses

Kind Regards

Apoorva

[Kangkana]

There is a new Scenario coming on intercompany Sales in SAP Two Tier . so that will be able to cover up this usecase

[apoorvas]

Thank you, but could you please elaborate on SAP Two tier ?