As described in previous units, there are several opinions related to the execution of production planning in SAP S/4HANA - with or without the add-on for embedded production planning and detailed scheduling (PP/DS). To combine both planning philosophies is the challenge of MRP Live.
MRP Live can combine both algorithms, MRP in SAP S/4HANA, and advanced planning in PP/DS.
For all materials that are activated for PP/DS using the advanced planning flag in the location, planning a product in PP/DS will be executed. For all other products, the planning remains in SAP S/4HANA. MRP Live can combine both planning algorithms in one planning run.
This means that MRP Live executes the PP/DS planning and the production planning in SAP S/4HANA in parallel with one constraint. MRP Live planning takes the standard heuristic from the Global Parameters and Defaults of the customizing or the heuristic from the location product into account.
If you are using a planning run with a setup of various heuristics, this can lead to the planning your demands using different detailed heuristics. After the PP/DS planning run, MRP Live should be executed to plan the non PP/DS based on the results of the PP/DS materials. During this planning run in SAP S/4 HANA, MRP Live also recalculates the PP/DS products and reschedules these receipts dates and times. This means that the results from the detailed planning run are gone.
This undesirable behavior was also valid in an SAP/ECC and APO/ PP/DS scenario. The solution there was to assign the PP/DS materials the special MRP type X0. In an SAP S/4HANA PP/DS scenario, this changed. Here, you have to exclude these products in the definition of the planning scope, for example, by using the material number as a selection or a different MRP Planner assigned to the PP/DS materials.