Solution : https://service.sap.com/sap/support/notes/309824 (SAP Service marketplace login required)
Key words : 
/bw=> sap business information warehouse => release specific information  -> select relevant release    -> front end patches, /bw=> sap business information warehouse => release specific information  -> select relevant release, menu path 'system' -> 'status' -> 'component information', --> infoobject/infosource--> source system                __________________________________--> infopackage, release-specific information page, transaction 'spam' front end release, business information warehouse, 'frontend patches'               download bw support packages, front end support package level    -->, latest front end support package
Related Notes : 
       
| 1229206 | Front end check tool SAPBExC.xla (BW 3.x and BI 7.x) | 
| 788393 | Query execution: Bookmark for reproducing errors | 
| 387490 | Required specifications in messages for BW-WHM | 
| 381530 | BW info of Support Package levels | 
| 376997 | BW customer messages with priority 1 (very high) | 
| 375631 | Extract of BW Support Strategy | 
| 370928 | Good OSS messages for BW-BCT | 
| 214826 | BW 1.2 Frontend checktool sapbexc.xla | 
| 197746 | Maint. strategy: Internet Transaction Server (ITS) | 
| 197460 | BW Frontend Checktool sapbexc.xla | 
| 195715 | Service connection types "BW RFC" and "BW GUI" | 
| 159983 | Release specific Information | 
| 149809 | Procedure f. errors in OLE DB for OLAP Interface | 
| 147218 | SAP APO Demand Planning - datamart ==> BW patches | 
| 142705 | Files for the BW support | 
| 138937 | BW-BEX problem must be examined in the system | 
| 137153 | Version of the BW frontend programs | 
| 120632 | BW frontend patch installation | 
| 112458 | Trace log in the Business Explorer | 
| 108103 | Overview: Notes on the R/3 Add-on BW-BCT | 
| 68689 | Data for setting up remote connection |