Solution : https://service.sap.com/sap/support/notes/460180 (SAP Service marketplace login required)
Key words : 
additional key words rm06ellb me2o resb, sc stock monitoring list, prerequisites solution implement, transaction me2o, stock monitoring, stock subcontracting, purchase order, performance problems, performance improvement, performance
Related Notes : 
       
| 508132 | AFS Performance in ME2O - SC Stock monitoring report | 
| 458938 | FAQ: Subcontracting stock monitoring list, transaction ME2O |