Default Storage Location

Hi Gurus,

Could you please help me the understand the reason for the below issue and how it can be addressed.

Despite maintaining all the required settings in OVL3 and OVL2, the system fails to defaul the storage location for few materials in a sales order. Our requirement is to default the storage location in the sales order which could be copied over the delivery.

The business issue is, many users fail to enter the sloc when creating a delivery which ends up in Idoc errors. In order to address this issue, we want the storage location field in the delivery to be defaulted.

Please help me with your invaluable ideas.

Many Thanks

Kumar