Hello Keser,
There are many factors that influence that behaviour. For a starter, there is the question for which worklist (POWL) are you experiencing long runtimes (OTR? DTR?).
Are there any enhancements in the underlying BO Query? Are the default selection criteria, or individual ones?
I suggest to execute an SQL trace to identify which table is responsible of the long runtime. Additionally, log a SAT trace to check the runtime of the ABAP cosing involved.
Regards,
Dragos