Order Number to be updated on the SR

Summary:

We have a requirement where Order Number should be updated on the SR when an order is created from Parts Order tab. Since adding order lines and creating an order from parts order tab is not triggering any action(like Before Update) on SR, we cannot achieve this through a trigger directly.

We earlier achieved this by created a custom trigger(Before update) with a webservice call to the salesOrdersForOrderHub with SourceTransactionId as SrId and get the order number and updates the field on the SR. But this trigger will fire for every update on the SR and is impacting the SR performance.