sheduling issue in operatin level subcontracting

hi friends,

I am doing subcontracting in operation level . Before releasing i have sheduleed the operations and and after the order is release i started operation confirmation in co11n. But then i am introducing external processing controll key PP02 in the operatin say 5 th operation and this subcontracting process takes say 2 days. likewise i have to send any operation to the subcontractors

Here in this point i want to again shedule the remaining operations .

I have maintained shedule external operation chek in controll key PP02.

BUT WHEN I GO FOR SHEDULING RUN AGAIN SYSTEM IS NOT SHIFTING THE DATES WHICH IT HAS SHEDULED BEFORE

so how i can perform sheduling in this senario ?

Please suggest me on this issue?

Regards

om