how to do partial allocation for sales order in MTO

Hi Experts,

          I have a scenario that is i would like to do partial delivery  for  a sales order in MTO scenario.we are using SAP AFS.

          So,I have done  allocation run for a sales order  which contains AFS material and quantity is allocated fully.But in my scenario , i want to change the quantity at the time of allocation manually against sales order(partially deliver). Is it possible to achieve this?

Thanks & Regards,

Deepika.