Allocation 
Use
With the aid of the allocation settings you can determine which principle the system should use to distribute existing material quantities among the individual requirements. If there is not enough stock, the allocation can either be according to the FIFO principle or the principle of equal distribution. When allocating with FIFO (first-in-first-out), the existing stock is assigned to the requirements according to the existing sorting. That means requirements that have a high priority due to the requirements sorting will be fully allocated, while requirements with a lower prioritization get little or no stock and therefore cannot be released. When allocating with equal distribution, existing stock can be equally distributed among the individual requirements of an allocation group according to certain rules.
Prerequisites
To carry out an allocation using the principle of equal distribution, you must form allocation groups by using requirements grouping. You can store the respective allocation logic in the related release rule for the different allocation groups.
Features
Allocation Logic
With allocation logic you can determine which principle should be used for the allocation. The allocation logic consists of the following components:
· ARun Function Module for the Allocation Preparation
The ARun function module for preparing the allocation determines the field contents for the internal requirements sorting. Here you can use one of two function modules:
¡ J_3AR_ALLOCATION_PREPARE_1: Use this function module if you want to sort at schedule line level first.
¡ J_3AR_ALLOCATION_PREPARE_2: Use this function module if you want to sort at header and item level first.
· Allocation logic
By selecting the relevant radio button, you control whether the allocation takes place according to the FIFO principle or the equal distribution principle.
You can also use the option Only upto Rlease Quantity. This option only applies if a requirement cannot be fulfilled completely. If there is not enough stock available, the system will allocate up to the release quantity (release percentage on the schedule line level).
The following example describes the allocation results that the different settings of the allocation logic can lead to:
In Case 1, the allocation is carried out according to the FIFO logic. The requirements of the first allocation group are completely fulfilled. The remaining quantity of 25 is only sufficient to fulfill the first requirement of group 2 up to the minimum quota.
In Case 2, the allocation is carried out using an equal distribution combined with a material shortage logic up to the minimum release quantity. After the requirements of the first allocation group are also completely covered, the remaining quantity is equally distributed among the requirements of the second group.
In Case 3, a FIFO distribution with a material shortage logic up to the confirmed quantity is set in the allocation logic. Since a maximum quantity of 70% is entered in the release rule, the allocation from the sales order is carried out up to this value instead up to the confirmed quantity.
In Case 4 there is also a material shortage logic up to the confirmed quantity used. Since an equal 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 allocation group, therefore an allocation of 28 pieces to requirement 3).
Allocation
Here you can determine whether stock and requirements categories are taken into account during the allocation run. Using the allocation, the system is told whether and in which form the category check should be executed. The category check can be carried out in the following levels:
...
1. No category check is carried out. You make this selection if you do not use stock and requirements categories in your business processes.
2. The system only checks whether valid combinations of stock and requirement segments exist for the respective coverage strategies (controlled via the material master). This option might be useful when using the preview mode because at this point in time it is not necessary to carry out a completely detailed category check. We recommend using this option for runtime reasons.
3. The allocation run executes a complete and thorough category check in all the requirements you have selected. Based on the category sequence in your Customizing, each schedule line of each item in an order is checked to see whether a matching stock segment with physical warehouse stock exists for this requirements segment, so that it can be ultimately allocated. This variant of the category check might cause a somewhat longer runtime. The runtime can be increased based on different criteria, such as the number of possibly existing categories plus the number of requirements to be selected. The more categories must be checked for your materials and the higher the number of requirements found, the longer the runtime will be.
See also Allocation Against Future Receipts.
Note
You can use different release rules for different requirements within an allocation run (see Release Rules, Requirements Grouping). For these requirements you can use an allocation logic that deviates from the logic you maintained in the allocation type. Enter the requested allocation logics in the corresponding release rules.