Allocation 
You use the allocation logic to determine the strategy that the system uses to distribute existing quantities to individual requirements. Allocation can be based on the FIFO (first-in-first-out) principle or the principle of proportionate distribution (spread logic). When you allocate using FIFO logic, the existing stock is assigned to the requirements according to the existing sorting. That means, the requirements that have a high priority (due to the requirements sorting) are fully allocated, while requirements with a lower priority are allocated little or no stock, and therefore cannot be released. When you use spread stock logic for allocation, existing stock can be proportionally distributed to the individual requirements according to certain rules.
The order allocation run results in assignments that are either released for delivery or reserved for delivery at a later date. These assignments have the following statuses depending on the result of the release check:
Fix (F): The stock is fixed and the outbound delivery is possible (when a release check is successful)
Fix and Hold (H): The stock is on hold and the outbound delivery cannot be created (though the release check successful)
Reserve (R): The stock is reserved.
On Delivery (D): The order is on track for delivery.
Prerequisites
To carry out an allocation using spread logic, you must create allocation groups using requirements grouping rules. You can store the allocation logic in the corresponding release rule for the allocation groups.
Features
Allocation Logic
You can use the allocation logic to specify the strategy for allocating existing stock during an order allocation run. You can choose the allocation logic in Customizing under 
Logistics - General 
SAP Fashion Management Order Allocation Run (ARun) Online ARun Allocation Logic Maintain Allocation Logic 
.
You select the relevant radio button to determine whether the allocation takes place according to the FIFO principle or the spread principle. You can also use the Only Up To Release Quantity option if a requirement cannot be fulfilled completely. If there is not enough stock available, the system allocates up to the release quantity (specified release percentage at schedule line level). The following example shows the allocation results for different of allocation logic settings:
Results for Different of Allocation Logic Settings
In case 1 (FIFO), the allocation is carried out using the FIFO logic. The requirements of the Group 1 are completely fulfilled. The remaining quantity of 25 is sufficient to fulfill the first requirement of Group 2 up to the minimum quota.
In case 2 (spread distribution), the allocation is carried out using spread distribution combined with a material shortage logic up to the minimum release quantity. After the requirements of Group 1 are also completely covered, the remaining quantity is equally distributed among the requirements of Group 2.
In Case 3 (FIFO at Max. Quota), allocation is carried out using FIFO distribution with stock shortage logic up to the confirmed quantity is set in the allocation logic. Since a maximum quantity of 70% was entered in the release rule, the allocation from the order is carried out up to this value instead of up to the confirmed quantity.
In Case 4 (Spread Distribution at Max. Quota), allocation is carried out using spread distribution logic and stock shortage logic up to the confirmed quantity is used. Since spread distribution is used here, the system equally allocates the remaining 55 pieces to the requirements of Group 2 (with the remaining quantity logic from the start of the current group, therefore an allocation of 28 pieces to Group 3).
Note
The following features are not supported when you used spread distribution logic as the allocation strategy:
Dynamic Stock Sorting: This feature is used to prioritize different stock types so that the one with the highest priority is allocated first.
Delivery Scheduling: This feature is used to ensure timely delivery to your customer.
Field Checks: The field checks that you select when your create an allocation rule are not supported.
You can define these features in Customizing under Logistics-General SAP Fashion Management Order Allocation Run (ARun) ARun Details Allocation Logic Maintain Rules for Allocation .