Solution : https://service.sap.com/sap/support/notes/139660 (SAP Service marketplace login required)
Key words : 
interval scale limits xkomv-kstbm, additional key words vf02, interval scale limits, program error occurs, kzbzg ca 'mnop', pricing type 'a', header condition screen, condition detail screen, interval scale record, periodic billing plan
Related Notes : 
       
| 315453 | Interval scale determination for credit memos | 
| 139765 | Interval scales in the billing doc. w. Note 102468 | 
| 113526 | Rounding problem for interval scales | 
| 102468 | Interval scale | 
| 43551 | Rounding problem in billing plan |