Testing IDOC basic type DELVRY03

Hi,

Can anyone tell me how can i test DELVRY03 idoc for ASN. The Idoc is not being triggered from any document as the data is coming from external system to the Ztable and I don't know how IDOC should be triggered.

Function module is Z_ZZ_IDOC_OUTPUT_DELVRY.

Message Type DESADV.

Can anyone tell me in this scenario until the desicion is made for triggering option, can i test the IDOC somehow and check the changes in debugging mode.

Regards

Rinku