PO historical data migration

Hi guys,

my client needs to migrate the PO open items with historical data from source SAP1 to the target SAP2 system. that's mean to migrate:

- GR and IR not done

- GR done, IR not done

- partial GR and/or IR

- GR and IR done but not yet cleared

- Return  or Reversal on a GR/IR

Have you any suggestion on strategy to be applied?

How to proceed with FI open items migration to avoid a double posting?

With which methodology/tool you'd suggest to apply? LSMW?

Thank you for any your support.

kr

RP