In the last part of the series, we discussed simplified sourcing in SAP S/4 HANA. I mentioned in part 3 that we would talk about business partners next, but I realise that it is logical first to discuss Material Requirement Planning (MRP) live as a follow-on topic.
In my view, two main enablers behind the changes and optimisation in the material requirement planning in S/4 HANAare as follows.
- Agility and speed powered by HANA In-memory database
- Simplification and redesigning in S/4 HANA with logic written in SQL-Script
MRP live on HANA is wholly redesigned with planning logic written in SQL-Script, which runs on the database server. It improved the runtime of MRP drastically.
From the business user perspective various transactions available in SAP Business Suite viz. MD01, MD02, MD03, MD40,MD41, MD42 and MD43 etc. is harmonised into one single transaction MD01N ( MRP Live). We can execute planning run for one or multiple plants, multilevel single-item planning, single-level single-item planning etc. in MRP live. Also, we can execute both Master Production Scheduling (MPS) and Material Requirement Planning (MRP) in MD01N. "Material Scope" field in MRP live selection screen influence whether all material is selected or only materials which are marked for MPS is considered.
In MRP Live selection screen we have two additional fields "Product Group" and "MRP Controller" to filter the materials are selected for planning.
In SAP Business Suite few compromises were made to compensate for the database capability and technology available. In S/4 HANA powered by HANA database, these points are optimised and further improved.
Planning horizon - Planning horizon is the time period within which MRP considers the demand for requirement planning. Planning inside the planning horizon was introduced to compensate for the MRP runtime performance. In S/4 HANA planning horizon concept is deprecated and MRP plans for all the demand in the time horizon. It is possible now due to the HANA in-memory performance. In terms of MRP run setting it means that in MRP live Processing key field is no more available.
Note: Review the background MRP run variants after conversion from SAP business suite to SAP S/4 HANA as variants with processing key 'NETPL' will not work.
Planning File - As MRP within the planning horizon is not supported any more in S/4 HANA hence planning file entries is also adjusted as per it. There is no separate indicator to indicate if there is any change in materials (from planning perspective) within the planning horizon. There is one single flag to indicate any change in material for the entire time horizon.
Performance Analysis - In SAP Business Suite program RMMDMONI(Technical Statistics of the planning run) and RMMDPERF (Technical Statistics for the planning run- material hit list) program is available to analyse the MRP performance.
In S/4 HANA MRP run performance can be checked using the T-code MD_MRP_PERFLOG. A new field is introduced in the MRP live selection screen to name the log file. We do not have MRP run performance analysis (similar to program RMMDPERF) per material available in S/4 HANA.
Cross Plant Planning - In SAP Business Suite during planning run for material in supplying and receiving plant is achieved by "scope of planning".Going forward in MRP live a new field "Stock Transfer Materials" is introduced to plan materials in the supplying plants during the planning run for the receiving plant.
MRP Area - In SAP Business Suite we can exclude material from plant level MRP
run and plan separately by using storage location MRP indicator. As an alternative similar result can be achieved by using MRP areas.
In S/4 HANA Planning in storage location level is possible only with MRP area. In S/4 HANA system MRP only plans on plant and MRP area level. To exclude material from plant level in MRP run we need to maintain storage location MRP area with MRP type 'ND'.
MRP List - MRP list in SAP business suite provides the demand and supply snapshot at the time of last MRP run. Requirement list can be retrieved quickly, and material deficit can be identified in near real-time with HANA database high performance and code optimisation.
In S/4 HANA MRP list, which used to show outdated snapshot, is not available. FIORI app like monitor material coverage can be used to get a real-time view of the supply/demand.
Requirement planning for period lot sizing procedure - In SAP Business Suite, the start of the period for period lot-sizing procedure is determined based on the first requirement date. In MRP live the start of the period is calculated based on the date on which MRP is run. For example, if we have weekly lot size maintained for a material with a period lot size of 2 weeks and requirement date is equal to start of the period then MRP run at the start of week 1 will result into the different result as shown below.
Considering the functional and technical complexity of MRP, porting the code base and logic written in ABAP to SQL-Script which runs on the database server is not straightforward. SAP plans to introduce new functionality in MRP live ( MD01N) at a regular interval. Please refer the SAP note 1914010 (which is updated as new planning feature is introduced in MRP live) to learn the restrictions for planning in MRP Live on HANA.
We can get the list of materials which cannot be planned in MRP live ( as per current restrictions) by executing the report PPH_CHECK_MRP_ON_HANA. These materials need to be planned in classic MRP.
In the next series, I will discuss the business partner approach in S/4 HANA for customer and vendors.
Please follow the link to access the part 1, part 2, and part 3 series of the blog
