SQL & PL/SQL

Hi,

In Oracle 11g r2

CREATE OR REPLACE PROCEDURE p_tst
AS
BEGIN
   DBMS_SCHEDULER.CREATE_CHAIN (chain_name            => 'CHAIN_DELTA1',
                                rule_set_name         => NULL,
                                evaluation_interval   => NULL,
                                comments              => NULL);
END;
--=================================
EXEC p_tst;

I am facing the error. ORA-01031: insufficient privileges.
I have DBA role assigned to my userid. what might be the reason for the error?

Regards,
Manikya.