Valid source of supply can be maintained in various means like schedule agreement, contracts, purchase info records. In ECC, MRP determines source of supply referring to source list and quota arrangement. In S4 MRP live, selection of source is predefined where source list and quota arrangement usage in material master is not mandate. This document explains the predefined logic in selection of source of supply in S4 MRP Live run.
Simplified Sourcing Determination in S/4 HANA, MRP Live run
In general, MRP determines material requirement date, quantity and source of supply. Sequence of actions are determine material shortage, lot sizing and then source of supply.
In case of several source of supply, source is determined based on quota arrangements. If quota arrangement is not available and several source of supply exist for the same material, plant, quantity, and date, source determination gives preference to production versions over delivery schedules, delivery schedules over purchasing contracts, and purchasing contracts over purchasing info records. If sourcing selects a production version as source of supply, then the material receipt is going to be a planned order. If sourcing selects a purchasing info record or contracts, then the planned material receipt is going to be a purchase requisition. If sourcing selects a schedule agreement, then the planned material receipt is going to be a delivery schedules. (Refer SAP note: 2268069 - S4TWL - Simplified Sourcing)
Role of Source list :
Though source list is not mandate, if a source is maintained in source list with MRP indicator as ‘1’ or '2', it has highest priority for MRP live.
Vendor, contracts or Schedule agreement can be blocked for MRP in source list for a period
When source of supply like schedule agreement, contracts and info records are maintained, a CDS view (table view: CDS_M_PUR_SOS_B) is created and field: PRIORITY is updated with priority for selection of source in MRP live run. In MRP live run will select the appropriate source of supply based on priority number 1 to 12. (Refer SAP note: 2614920 - Sourcing priority during MRP in S/4 HANA system)
In S/4HANA, the purpose of source list in source determination are last priority for selection of source and exclusively used to blocking the sources.