If you would like to execute the source allocation and reschedule purchase requisitions that have not been assigned, you can base each source allocation run on one of the following logics:

• Source allocation scheduling logic I
  If you choose this logic, the system will sequentially assign open purchase requisitions in a primary program run to exactly those open capacities, to which the purchase requisitions should be allotted according to their delivery date. All of the purchase requisitions that cannot be assigned during this first program run will be rescheduled in a block. In a second program run, the system will try to assign all of the remaining open purchase requisitions to the capacity periods that are closest to the capacity period originally selected. Purchase requisitions that cannot be assigned during the second program run will then be rescheduled and run through a third allocation. We recommend that you choose this logic if it is more crucial for you to meet the delivery date than to prioritize the purchase requisitions with the sort criteria.
• Source allocation scheduling logic II
  If you choose this logic, the system sequentially assigns open purchase requisitions to open capacity periods. Unlike the scheduling logic I, the system processes one purchase requisition at a time and moves each individual purchase requisition until it can be assigned to a free capacity period. Only after the first purchase requisition in the list has been assigned does the system begin with the allocation of the second. Once the second purchase requisition has been successfully allocated, the allocation of the third will follow. This procedure is repeated until all open purchase requisitions have been allocated. Since this logic is directly aimed at each individual purchase requisition, the sort criteria play an especially important role. You can make sure, for example, that all purchase requisitions of a specific item category are allocated to free capacities first.

The source allocation with scheduling logic I or II requires the following settings (Logistics ® Materials Management ® Source Allocation ® With Source Allocation Scheduling Logic I or II) :

• Enter a version and a version description.
• Specify in the group box Purchase Requisition Scheduling whether purchase requisitions that have not been allocated should be rescheduled forwards or backwards.