Scenario: Your SAP system Kernel has been patched.
You would like to see the patch history of the system and you are running on Windows and SQL Server.
You can view the patch history for a DLL or EXEcutable (such as disp+work) by querying a table in the SQL Server database as follows (changing the <SID>):
SQL> select * from <SID>.MSSDWDLLS
order by DLLNAME, HOSTNAME, DLLPATH, LASTDATE, LASTTIME;
The results will provide a complete traceable history of the system including the previous identity of the SAP system, the different application instances and any inconsistencies in the DLL versions.