Unlock R12 APPS user account...

Unlocking APPS user account:

Check the status of the user account using sql query ,connect system/sys account and check the account status.

SQL> select username,account_status from dba_users where username='APPS';

USERNAME                  ACCOUNT_STATUS
------------------------------ --------------------------------
APPS                           LOCKED

Account status locked,

• Using below query you can check the "FALIED LOGIN ATTEMPTS" 
• You have given wrong password more than 10 times so account locked,

SQL> select RESOURCE_NAME,RESOURCE_TYPE,LIMIT from dba_profiles where profile='DEFAULT';  
                                                                             
RESOURCE_NAME                    RESOURCE LIMIT
-------------------------------- -------- ----------------------------------------
COMPOSITE_LIMIT                  KERNEL   UNLIMITED
SESSIONS_PER_USER                KERNEL   UNLIMITED
CPU_PER_SESSION                  KERNEL   UNLIMITED
CPU_PER_CALL                     KERNEL   UNLIMITED
LOGICAL_READS_PER_SESSION        KERNEL   UNLIMITED
LOGICAL_READS_PER_CALL           KERNEL   UNLIMITED
IDLE_TIME                        KERNEL   UNLIMITED
CONNECT_TIME                     KERNEL   UNLIMITED
PRIVATE_SGA                      KERNEL   UNLIMITED
FAILED_LOGIN_ATTEMPTS            PASSWORD 10
PASSWORD_LIFE_TIME               PASSWORD UNLIMITED

RESOURCE_NAME                    RESOURCE LIMIT
-------------------------------- -------- ----------------------------------------
PASSWORD_REUSE_TIME              PASSWORD UNLIMITED
PASSWORD_REUSE_MAX               PASSWORD UNLIMITED
PASSWORD_VERIFY_FUNCTION         PASSWORD NULL
PASSWORD_LOCK_TIME               PASSWORD UNLIMITED
PASSWORD_GRACE_TIME              PASSWORD UNLIMITED

16 rows selected.

To unlock the APPS user account,

[oradev@erp2 ~]$ sqlplus / as sysdba

SQL*Plus: Release 11.1.0.7.0 - Production on Thu Aug 10 15:35:10 2017

Copyright (c) 1982, 2008, Oracle.  All rights reserved.

Connected to:

Oracle Database 11g Enterprise Edition Release 11.1.0.7.0 - 64bit Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL>alter user apps account unlock;

user altered.

SQL> select username,account_status from dba_users where username='APPS';

USERNAME                       ACCOUNT_STATUS

------------------------------ --------------------------------

APPS                           OPEN

We can follow below solutions also:

You can change the "FALIED LOGIN ATTEMPTS" to unlimited, to create a new profile with unlimited attempt.and assingn the profile to apps users

SQL> CREATE PROFILE APPS_DEFAULT LIMIT

 COMPOSITE_LIMIT UNLIMITED

 SESSIONS_PER_USER UNLIMITED

 CPU_PER_SESSION UNLIMITED

 CPU_PER_CALL UNLIMITED

 LOGICAL_READS_PER_SESSION UNLIMITED

 LOGICAL_READS_PER_CALL UNLIMITED

 IDLE_TIME UNLIMITED

 CONNECT_TIME UNLIMITED

 PRIVATE_SGA UNLIMITED

 FAILED_LOGIN_ATTEMPTS UNLIMITED

 PASSWORD_LIFE_TIME UNLIMITED

 PASSWORD_REUSE_TIME UNLIMITED

 PASSWORD_REUSE_MAX UNLIMITED

 PASSWORD_VERIFY_FUNCTION NULL

 PASSWORD_LOCK_TIME UNLIMITED

 PASSWORD_GRACE_TIME UNLIMITED;

Profile created.

Assign the newly created profile to the user as default profile.

SQL> ALTER USER appusr PROFILE appusr_default;

Unlock the user account:

SQL> alter user apps account unlock;

user altered.

Best Regards.