Hi MOhan,
As per SAP standard functionality, Historical orders are created
1) to have a backup of maintenance history of Functional locations/Equipment ( Technical objects)
2) During data migration form Legacy system to SAP system OR SAP to SAP
3) You can not do Time confirmation on Historical orders
4) You can not do financial posting on historical orders
In general scenario, we create these historical orders using BDC during our Cut-over activities.
Check below screenshot for your reference.
