This article is relevant for Business Suite MRP Live run(MD01N).
Consistent planning file is quintessential to a successful planning run. Basically, planning file is used to determine the sequence of planning materials in an MRP run. Just like an assembly line in a factory, materials are posted one after the other for planning. The system uses the Low-Level Code(LLC) to determine this sequence. The material with the lowest LLC is planned first.
So, to keep Material Requirements Planning line smooth, the LLCs of materials in a planning file should always be in sync with the LLC of material master.
However, sometimes the LLC of planning file goes out of sync with the one in Material Master. This could happen for several reasons and each such instance may have a different cause; which could be a topic of discussion for another day.
The out of sync LLC could have different repercussions during planning run; mainly causing a material to be planned out of turn in the sequence, for example, and sometimes though rarely could lead to stoppage of MRP run. This could be the most undesired outcome of any planning run.
Is there a way to avoid getting into this situation?
MRP Live run(MD01N) in Business Suite on HANA (EhP7 and EhP8 of ERP) has a mechanism to check and correct this inconsistency automatically. During MRP Live run the system first searches the planning file entries for sync errors and then corrects them. The MRP run then continues with the planning of selected materials.
The system searches the following inconsistencies:
- One entry exists in the planning file (. e.g. DBVM table) for the material but LLC (DISTT field) in a planning file isn’t equal to the one in material master(MARA). DBVM~DISTT <> MARA~DISTT.
- Several entries in the planning file exist for the same material number(MATNR) and MRP Area(BERID) combination. In this case, it searches all those entries where planning file LLC and material master LLC do not match. DBVM~DISTT <> MARA~DISTT for MATNR, BERID combination.
- It ignores entries with blank LLC in the material master and LLC ‘999’ in planning file.
This check must be kept as simple as possible since it is very much part of the planning run. Complicating it would lead to performance problems.
The system then replaces LLC of all these inconsistent entries in planning file with the one in material master and stores them on the DB table. The planning run continues without any hitches though there were problems; truly a self-healing mechanism.
This check and auto-correct works only for the materials selected by the MRP run.
I have come across some instances where the number of inconsistencies was considerably huge and MRP run could not be continued further for technical reasons. The size of the resulting query would be huge, resulting in the MRP run to terminate in a dump.
An example of the short dump:
How to approach this situation?
In such a scenario it would be required to first correct the planning file inconsistencies and then run MRP Live. To correct the inconsistencies, you must run the report RMMDVM10 for all plants or MRP areas in the system. You must make sure the majority of the materials (if not all) are checked for consistency of planning file. The report will generate a log of all the corrected entries.
Snapshot of report RMMDVM10.
Subsequent MRP runs should now be successful, even if some inconsistencies do exist then the MRP Live run will correct them.
This remediation of planning file inconsistencies holds good only for MD01N in Business Suite on HANA (EhP7 and EhP8) and NOT for S/4HANA MRP Live run. S/4HANA has a new planning file table PPH_DBVM – note 2268088. This does not have LLC as a field, but rather it is read from the material master during the planning run. So, the need for synchronization of LLCs is unnecessary in S/4HANA MRP Live.