BPCS mechanism to correct overloaded planned orders

  
Hi,

If after running CRP (Capacity Reqmnt. Planning), it is found that, the 
capacity is insufficient to take care of the planned orders i.e. overloaded 
plan, there are 2 ways, either to reduce order Qty. or off-load (sub-contract) 
the job or do overtime. 
However, if off-loading can't be done due to some reason, is there any 
mechanism in BPCS that will automatically correct the customer order Qty. 
taking into consideration capacity constraint ?
or is it only in the form of messages to 'Expedite' the planned order or how is 
it ?

regards,
Prashanth