These SQL Server performance problems  could be avoided by some proactive reporting \  database server maintenance .
 1)       Fragmentation
2)       No Indexes or Index Problems
3)       SQL Server Backups at  peak usage time
4)       Inefficient queries – Bad Estimates creating hash joins and index scans
5)       Incorrect plan used by Stored Procedure
6)       Inaccurate\missing statistics
7)       TempDB performance issues
8)       Log Files on incorrect drive
9)       To much data retrieval
10)      DBAs not troubleshooting performance problems properly