Solution : https://service.sap.com/sap/support/notes/459694 (SAP Service marketplace login required)
Key words : 
'cover dependent requirements immediately' planning procedure permits, 'cover dependent requirements immediately' planning procedure ensures, 'automatic planning immediately' planning procedure sparingly, 'cover dependent requirements immediately' planning procedure, performing pp/ds optimization periodically, 'automatic planning immediately' planning procedure, existing receipt elements remain unchanged, strategy profile permits forward scheduling, planning-related minimum intervals, planning run' planning procedure
Related Notes : 
       
| 1167216 | Usage of Product Priority | 
| 663297 | Strategy settings for planning (documentation) | 
| 551124 | APO: Finite scheduling with MRP heuristic (documentation) | 
| 520561 | Maintaining product master in R/3 or in APO? | 
| 441102 | Consulting notes in PP/DS | 
| 426563 | CTP: Settings, system behavior and performance (docu) |