In reorder point planning, the system compares the available stock with the reorder point to determine the net requirements. If the available stock falls below the reorder point, the system triggers a procurement proposal for the material. The quantity of the procurement proposal depends on the lot size procedure that is defined in the material master. The lot size procedure determines how the system calculates the order quantity based on factors such as demand, costs, and storage space. There are different types of lot size procedures, such as static, periodic, or optimum lot size. Reference: [Production Planning with SAP S/4HANA], page 156; [SAP Help Portal: Lot Size Calculation].

Thelow-level codein SAP S/4HANA (visible in MD04 or calculated during MRP) indicates the deepest level at which a material appears in any BOM across all products, starting from 000 (finished goods) downward. Its key features are:
* To determine how costs are rolled up by product costing(B): In Product Costing (CO-PC), the low-level code ensures costs are calculated bottom-up, starting with the lowest-level components (e.g., raw materials) and rolling up through assemblies to the finished product (transaction CK11N). This guarantees accurate cost aggregation.
* To determine the sequence in which materials are planned in MRP(C): During MRP (MD01/MD02), the system plans materials in ascending order of low-level codes (lowest first), ensuring dependent requirements for lower-level components are calculated before higher-level assemblies, avoiding planning gaps.
Priority of alternative components in ATP(A) is managed by BOM alternative item strategies (e.g., 100% check), not low-level codes.Use of sub-items in BOM(D) is defined by item categories (e.g., "R"), not influenced by low-level codes. This is per SAP's planning and costing logic.