The system's decision to create a planned order versus a purchase requisition during an MRP run is primarily determined by two master data fields. The Procurement Type (field MARC-BESKZ) in the material master's MRP 2 view is the main indicator. A setting of 'E' (in-house production) or 'X' (both) leads to planned orders. A setting of 'F' (external procurement) typically leads to purchase requisitions.

However, for externally procured materials, the MRP Group (field MARC-DISGR) assigned in the MRP 1 view can override this default behavior. The MRP group contains a specific parameter ("Create purchase req.") that allows a planner to define whether MRP should create purchase requisitions directly, only within the opening period, or always create planned orders first.

B. Material type: This controls general attributes like valuation and which views are available for a material, but not the specific type of MRP procurement proposal.

C. MRP type: This determines the planning procedure (e.g., MRP, consumption-based planning), which dictates if and how a material is planned, not the resulting proposal type.

1. SAP S/4HANA Documentation, "Procurement Type": "The procurement type determines whether a material is produced in-house, procured externally, or both... For materials with procurement type F (external procurement), the planning run creates purchase requisitions." (This establishes the primary role of the Procurement Type).

Source: SAP Help Portal, S/4HANA 2023, Material Master (LO-MD-MM) -> Material Master Data -> MRP Data -> Procurement Type.

2. SAP S/4HANA Documentation, "MRP Group": "In the MRP group, you can maintain the parameter Create purchase requisition... With this parameter, you can control for materials that are procured externally whether the planning run is to create purchase requisitions or planned orders."

Source: SAP Help Portal, S/4HANA 2023, Production Planning and Control (PP) -> Material Requirements Planning (PP-MRP) -> MRP-Specific Material Master Data (PP-MRP-MD) -> MRP Group.

3. SAP S/4HANA Documentation, "Creation of Procurement Proposals": "For materials procured externally, the system can create either planned orders or purchase requisitions... You can override this setting in the MRP group for the material. The setting in the MRP group has a higher priority."

Source: SAP Help Portal, S/4HANA 2023, Production Planning and Control (PP) -> Material Requirements Planning (PP-MRP) -> MRP Run (PP-MRP-PR) -> Planning Process -> Creation of Procurement Proposals.