Skip to Content

MRP: Vendor is not selected and general problems on source determination


Problems on the source determination are very common on material requirements planning.

Generally, a vendor or scheduling agreement is defined on the source list, however, when MRP is executed, this vendor is not selected, MRP does not generated a schedule line or a quota arragement is not selected.

On this document you will find the most common causes for this issue and the most relevant consulting notes on this topic.

At the end of this document, you will also find more details about the programs involved on the MRP source determination, so that you can analyze problems in debug.

For more information about the source determination you can also refer to the following WIKIs:

MRP Source Determination for External Procurement using a Source List - ERP Manufacturing (PP) - SCN Wiki

MRP Source determination using a quota arrangement - ERP Manufacturing (PP) - SCN Wiki

1 - MRP does not generate schedule lines

See the following note for more details:

2 - Problems on validity

For design reasons, MRP checks the validity of the source list, quota arrangement and scheduling agreement according to the REQUIREMENT date.

In some cases, the requirement is the past and the customizing settings don't allow the creation of a replenishment proposal in the past.

In this case, system checks the validity agains the requirement date and later runs a "today scheduling" to calculate the replenishment proposal dates. These dates may be within the source list or scheduling agreement validity, however, they will not be considered if the requirement is not withing the validty.

Check the note below for more details:

3 - A quota arrangement is not selected

The following note provides a very detailed explanation of the correct set up of a quota arrangement:

4 - The Target Quantity of the Schedule Agreement is not considered by MRP

According to the system standard design, the target quantity should not be considered by MRP.

A maximum quantity can be considered by means of the quota arrangement in the source determination.

Note below provides more details:

5 - BAdI MD_MODIFY_SOURCE is active

With this BAdI, you can create your own logic to select the vendor and it is possible to override the source list and quota arrangement settings.

6 - Inforecord missing on the purchase requisition

For performance reasons, the inforecord number is not copied to a purchase requisition created by MRP.

This system behavior is described on the following note:

7 - Quota arrangement is not considered on MRP area

On the standard system, quota arrangement is not considered at MRP area level or on a storage location planned separately.

A detailed explanation for the reasons of the system design and a modification to change the system behavior can be found on the following note:

8 - Technical analysis in debug

The starting point to debug is program LM61YF2M.

On form check_orderbuch you will see the source list being selected from table EORD and checked according to the validity.

If there is a quota arrangement, it will be checked on form check_quotierung (include LM61YF3D).

If there is a scheduling agreement, it will be read on function module ME_READ_OUTLINE_AGREEMENT_DISP.