SAP Knowledge Base Article - Public

3328466 - MRP is not scheduling procurement proposals in the past


When running MRP for a material, the MRP doesn't execute backward scheduling, the proposals are created in the future. MRP is only executing forward scheduling.


SAP S/4HANA Cloud.

Reproducing the Issue

  1. Go to Schedule MRP Run app
  2. Execute MRP for a material
  3. MRP execute forward scheduling and the proposals are created in the future.


Standard system behavior.


In S/4HANA Cloud, MRP doesn't allow start dates in the past for procurement proposals.

As an option, you might check whether the usage of a planning time fence (firming horizon) can be used in your scenario.

The planning time fence (e.g. equal to the replenishment lead time) would realize that appropriate procurement proposals inside this horizon will not be touched and rescheduled anymore by the MRP. Based on that they stay at their original dates even in subsequent MRPs and do not move anymore to the end of replenishment lead time based on the re-occurring forward scheduling. A disadvantage of such an approach is of course the fact that changes in the requirement situation (e.g. new demands) inside the planning time fence will be covered by procurement proposals at the end of the planning time fence.

As a general recommendation, never deactivate the rescheduling in MRP. The deactivation of the rescheduling horizon usually results in over-planning by the MRP as late receipts which are firmed somehow by appropriate business needs will not be used to cover the demands anymore. The MRP will create new procurement proposals even if they will get the same or later dates as the ignored firmed receipt.


start dates, procurement proposals, MRP, wrong, results, date, dates, current date, proposal , KBA , PP-MRP-2CL , Material Requirements Planning (Public Cloud) , PP-MRP , Material Requirements Planning , Problem


SAP S/4HANA Cloud all versions