Tcode SM51 takes long time to finish

Hi,

The Tcode take long time while executing.

Last week it was taking only 5 mins to complete, But since last 4days the Tcode MB51 takes more than 60 mins and time out error occurs.

Please advice, why the Tcode takes long time to complete.

Product details: ecc6.0

Database: Db2

Thanks,

Jena.