In SAP standard the subcontracting requirements are not considered in the long-term planning.
In transaction MS04 the subcontracting dependent requirements are not displayed.
You can find further information in the SAP note 311336.
With an implementation of BAdI MD_CHANGE_MRP_DATA using method CONSIDER_RESB, it is possible to make the subcontracting requirements relevant for long-term planning.
*–> set flag to consider SC dep. requirements in LTP
ch_no_exit_flags-ltp_subcon = ‘X’.
*–> set changed flag
ch_changed = ‘X’.