By default, the password lifetime is set to 180 days. If you face any problems caused by expired password (ORA-28001: the password has expired), change the password lifetime with this command:
ALTER PROFILE DEFAULT LIMIT PASSWORD_LIFE_TIME UNLIMITED;
There are more parameters you might want to consider setting according to your needs:
LIMIT COMPOSITE_LIMIT UNLIMITED
PASSWORD_REUSE_TIME UNLIMITED
PASSWORD_REUSE_MAX UNLIMITED
PASSWORD_VERIFY_FUNCTION NULL
PASSWORD_LOCK_TIME UNLIMITED
PASSWORD_GRACE_TIME UNLIMITED
FAILED_LOGIN_ATTEMPTS UNLIMITED
If the password has expired, must find out the affected users with this command:
SELECT USERNAME, ACCOUNT_STATUS FROM DBA_USERS where username LIKE '%_OPSS' or username LIKE '%_IAU%' or username LIKE '%_STB';
Then set the password that was set during the installation for each of these users:
ALTER USER <username> IDENTIFIED BY <password>;
COMMIT;