MD03 vs MDBT
I understand that MD03 is for single execution and MDBT is for background and for the full plant.
I execute MD03 for a specific material and the MRP list is generated the purch requisition is generated. I exit the transaction without saving.
I then execute MDBT, I created the variant with the same settings that I used in MD03. I then executed the variant using "Start Immediately".
I go to MD05 to see the result using "Individual access". I enter the exact material I used in MD03, but I get "No MRP List Exist".
Am I missing something? It generates an MRP List in MD03, but it does not generate an MRP List in MDBT. Please remember, that when I execute the MD03 I put a checkmark in "Display results before they are saved". I exit MD03 without saving.
Thanks in advance for your help!!!
There is no such thing as "it worked too well". Any planning file entries that were created, should have been created. The current planning situation is irrelevant.
MRP lists (the data you see displayed in MD05) are not created by MDAB, they are created by MRP (such as MDBT).
Normally, MDBT will check for the presence of a planning file entry. If none exist, it will bypass that material. Planning file entries are normally created when you create/change a material so as to be relevant for MRP. There are a couple of ways, though, that this creation may be missed. MDAB 'cleans up' these errors.
MD03 bypasses this planning file entry check. As long as the part has an MRP type in the material master that relevant for MRP, you can successfully run MD03 and create an MRP list.
MD05 displays the list created by a previous MRP run. MD05 may contain exception messages, or it may not. It is not carved in stone that every MD05 listing will have a new purchase requisition in it.
The frequency of running MDAB (and his brother, MDRE) is dependent upon the number of missing planning file entries you generate on a regular basis. Unless you are using substantial enhancements, you would be unlikely to need it more than once every few MRP runs. Some companies run it weekly, some run it monthly, companies with a very stable environment might run it even less. Read SAPs info on the subject: