Do you know why transactions MD04 and MD05 can display different exception messages?
Do you know why sometimes MRP does not plan a material?
Do you know why MRP does not consider the storage location for a subcontracting requirement?
Do you know if it possible that the MRP creates a separate procurement proposal for every requirement?
You can find the answer to this and to may other questions frequently asked to SAP on the MRP FAQ notes.
These notes are constantly reviewed and updated with new information.
Here you can find a list of these notes:
550568 FAQ: MRP run (MD01, MD02, MD03, MDBT,…)
553746 FAQ: Planning file entries in material requirements planning
550844 FAQ: MRP areas
568593 FAQ: Parallel planning run (MD01, MDBT and so on)
550014 FAQ: Source determinatn in the material requiremnts planning
549752 FAQ: MRP elements in transaction MD04/MD05
550441 FAQ: Exception messages in material requirements planning
550302 FAQ: Rescheduling check
550219 FAQ: Subcontracting in the material requirements planning
550038 FAQ: Order report / order tree
549193 FAQ: Error messages in the material requirements planning
855775 FAQ :MD43 and Planning mode
2012620 MRP: Problems with BAdIs
1992885 MD04: Problems with sales orders and deliveries