Create ORDRSP Idoc on creation, change or deletion of outbound delivery

We have ORDRSP Idocs being created when a sales order is created or modified. Now our customer would like an ORDRSP Idoc sent to them when the outbound delivery is created for the sales order. The reason that the customer would like an additional ORDRSP sent is because the time between the entry of the sales order and the creation of the outbound delivery may be a few weeks or more and the actual delivery may not be able to satisfy the quantity ordered. The customer is not set up to allow partial deliveries.

The customer uses the ORDRSP to feed into their billing system and would like updated quantities at delivery time. They do not want an ASN record.

Does anyone have any ideas or suggestions on how to trigger the ORDRSP Idoc when the delivery is created, modified or deleted? We are on SAP release ECC 6.0

Thanks for any help,

Russell