Solution : https://service.sap.com/sap/support/notes/1400993 (SAP Service marketplace login required)
Key words : 
depreciation calculation determines incorrect depreciation values, shortened fiscal year, defined reduction rules, relevant company code, individual period weighting, depreciation calculation, incorrect assets, annual depreciation, period weighting, transaction oayp
Related Notes : 
       
| 672255 | Shortened fiscal year/changing fiscal periods |