If you create a purchase requisition manually in SAP S/4HANA and the system determines several valid equivalent sources of supply, you must select the appropriate source manually from a list. If the system is to make this selection on its own, you can additionally use the source list.
The source list is a register of sources of supply for a material in a certain plant. Each source list record contains a validity period, a source of supply, and parameters that control the source of supply during this period. One of these parameters is used to define a source as your preferred source of supply. The source list also performs other functions that we will examine in this section.
The two figures below show the structure of a source list—once with the Manage Source Lists app and once with the SAP GUI transaction, Transaction ME01. For each material and plant, the source list contains a list of sources of supply that have certain characteristics within a certain validity period.
A source of supply is identified in the source list as follows:
- By the vendor number only: In this case, the source of supply is an info record. Although the number of the info record is not visible in the source list, it is unique based on the material number and the vendor number.
- By the vendor number, outline agreement number, and item: In this case, the source of supply is a scheduling agreement or a contract.
If another plant is a possible source of supply (stock transfer), enter the plant number in the PPl field of the SAP GUI transaction or in the Procurement Plant field of the SAP Fiori app and do not enter a vendor number or outline agreement item number. The plant is only determined as the source of supply for a purchase requisition item with item type U (stock transfer). For purchase requisitions that are created by the planning run, the materials require a corresponding special procurement type in the MRP data of the material master record.
Here are the options that the source list offers for managing sources of supply:
- Fix a source of supply for source determination: You can use the Fixed status in the SAP Fiori app or the Fix checkbox in the SAP GUI transaction to define a source of supply as the preferred source of supply for automatic sourcing for a certain period. This fixed source of supply is then always selected automatically, unless you have maintained a quota arrangement for the material (see the source determination logic described previously) and except during the MRP run. At any given time, only one source of the same category (e.g., an info record or an outline agreement item) can be marked as fixed. If you mark both an info record and an outline agreement item as fixed for the same period, the system will select the outline agreement item.
- Block a source of supply: The Blocked status in the SAP Fiori app or the Blk checkbox in the SAP GUI transaction allows you to block a source of supply for a certain period. If you block a source of supply, you cannot use the info record or outline agreement item in source determination, and you can create neither a purchase order nor a requisition using this supply source in this period.
- Set a source of supply to relevant for MRP or not: You can use the Materials Planning field in the SAP Fiori app or the MRP checkbox in the SAP GUI transaction to override the source determination logic during the planning run. If you set the indicator to 1 for a source of supply, this source of supply is selected during the MRP run and assigned to a purchase requisition. If a source of supply is a scheduling agreement item, you can set the indicator to 2, then the MRP run will create schedule lines for this scheduling agreement.
In the Manage Source Lists app, indicators or checkboxes are replaced by two dropdown fields. You can use the Status field to lock a source of supply or define it as fixed. You use the Materials Planning field to specify whether the source of supply is not relevant to MRP, whether it is to be assigned to purchase requisitions generated via MRP (corresponds to indicator 1), or whether schedule lines are to be generated via MRP (corresponds to indicator 2 and is only useful for scheduling agreements). The figure below shows the two fields and their possible values.
In summary, we can say that the source list is a management tool for sources of supply. A source list contains part or all the sources of supply of a material with properties (fixed, blocked, relevant to MRP) valid for a certain period. The use of source lists can be optional or mandatory. The mandatory use of source lists can be defined per material or even at the plant level. The next two figures show the plant-specific Purchasing view of a material. You can set the Source List Requirement indicator there.
Below shows the customizing path for setting the source list requirement at the plant level.
The final figure shows you the settings. In this example, no plant is subject to the source list requirement in the system.
If you declare the source lists as mandatory, a source list then assumes the role of a list of approved sources. You can only order a material from a certain supplier if an info record or an outline agreement exists for this vendor-material combination and this source of supply is registered in the source list.
Editor’s note: This post has been adapted from a section of the book SAP S/4HANA Sourcing and Procurement Certification Guide: Application Associate Exam by Fabienne Bourdelle.