BAPI_PRODORD_GET_DETAIL: connect results of header & component

Hello,

I use BAPI BAPI_PRODORD_GET_DETAIL to get detailed informations about production orders.

Now I need to assign the entries of result table HEADER to the corresponding entries in result table COMPONENT.

Conformance of

header-material EQ component-material AND header-production_plant EQ component-prod_plant

is not enough.

What are additional conditions, to ensure an unique assignation.

Thanks in advance,

Hubert