3626431 - Lot size of the purchase requisition generated by MRP is not as expected when using the "Replenishment up to maximum stock level" Lot-Sizing Procedure in reorder point planning

You are using the combination of "Reorder point planning" MRP type and "Replenish to maximum stock level" Lot-Sizing Procedure for a material. After the MRP run, the lot size of the purchase requisition generated is not as expected and cannot be explained. For example, the purchase requisition doesn't make the available stock to the maximum stock level, but to a negative value.

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SAP S/4HANA Cloud Public Edition

There are several factors which may influence the result of the lot size calculation.

1. The Formula.
   In configuration activity 101112 of the Lot-Sizing Procedure, there is a "Max. Stock Level" indicator which will determine which formula to use to calculate the lot size. 
   If the indicator is set as "1", the system calculates the lot size using the following formula:
   Lot size = maximum stock level + total requirements - current warehouse stock - existing fixed receipt elements
   If the indicator is set as " ", the system calculates the lot size in two steps using two formulas. The system then creates the order proposal using the greater of the two lot sizes.
   (Formula 1)
   Lot size = maximum stock level - current warehouse stock - existing fixed receipt elements
   (Formula 2)
   Lot size = reorder point + total requirements - current warehouse stock - existing fixed receipt elements
   
2. The Requirement.
   If the formula determined above contains a requirement relevant section, then it is important to figure out which requirements will be considered during the calculation. In the configuration activity 101171 of MRP type, there is a section to set which types of external requirements should be included.
   
3. The Replenishment Lead Time.
   If the Replenishment Lead Time is involved in the process, it is calculated as:
   Replenishment Lead Time = GR Processing Time + Purchasing Processing time+ Planned Delivery Time.
   Regarding this formula, there is one point to be noticed:
   When calculating the requirements to be considered, the Planned Delivery Time is retrieved from the master data. While when calculating the purchase requisition available date, the Planned Delivery Time is retrieved from sourcing documents, for example, purchasing info record or purchase contract. As a result, if the Planned Delivery Time maintained at the two places are different, the purchase requisition generated may mismatch with the requirements which it actually to fulfill, thus leads to a negative value at the stock level.
   
   

Go through the factors in the Cause section one by one and maintain the parameters properly. 

MRP, replenish to maximum stock level, lot-sizing procedure, planned delivery time, purchase contract, stock replenishment, GR processing time, inconsistent, reorder point planning, MRP type, 101112, 101171 , KBA , PP-MRP-2CL , Material Requirements Planning (Public Cloud) , Problem