SAP SD SUPORTE: S/4HANA Classical MRP vs MRP Live

Classical MRP:

The main function of material requirements planning is to guarantee material availability, that is, it is used to procure or produce the required quantities on time both for internal purposes and for sales and distribution. This process involves the monitoring of stocks and, in particular, the automatic creation of procurement proposals for purchasing and production.

In doing so, MRP tries to strike the best balance possible between

optimizing the service level and
minimizing costs and capital lockup.

The automatic planning run in MRP determines any shortages and creates the appropriate procurement elements. The system generates messages for critical parts and unusual situations so that you can rework the planning results in a specific area with problems.

MRP Live:

Using MRP Live, you can benefit from improved performance and execute the planning run in much shorter cycles. This means that you can execute several planning runs daily providing the MRP controller with the following benefits, for example:

More up-to-date supply and demand information on which to base decisions.
Faster reaction to demand changes reduces the risk of stock-outs and means that you can reduce safety stocks.
Match demand and supply more efficiently than was previously possible.
Identify and react to issues faster than was previously possible.

The report MRP Live (with the technical name PPH_MRP_DISPATCHER) is a copy of the report RMMRP000 and provides the following options for carrying out the planning run:

MRP Live (transaction MD01N) calls MRP on HANA
MRP Live (transaction MD01N) calls classic MRP

Planning selection MRP Live and Classical MRP

During the planning run, the system plans the materials according to the sequence determined by the low-level codes that are defined in the bill of materials. That is, for the first low-level code (0), the system determines which materials can be included in MRP Live on HANA and plans these first. In a second step, the system determines the materials with the same low-level code that could not be planned in MRP Live on HANA and then automatically plans these materials using classic MRP. Included in this second step are also the materials that were planned in MRP Live on HANA but for which an error occurred. Both the planning in MRP Live on HANA and classic MRP has to be completed for one low-level code before the system commences the planning of the next low-level code (1).

That is, during the planning process, the system divides the materials into groups:

Materials that can be planned using MRP Live on HANA
Materials that still have to be planned in classic MRP because:
- They require a planning feature that is not yet supported by MRP Live.
- You have set the Plan in Classic MRP indicator in transaction md_mrp_force_classic. In this report, the system displays all materials with active MRP views in the material master and you can define that the planning run is to be executed using classic MRP for individual materials. You should check which materials require the processing of a BAdI during the MRP run and always set this indicator for these materials.
Materials that cannot be planned in either MRP Live on HANA or in classic MRP because of inconsistent master data, for example. The system creates exception MRP lists for such materials that cannot be planned.