12.2 E-Business Suite Patching ADOP Phase Prepare Fails with Error '[UNEXPECTED]Error while validating worker count' (Doc ID 2137155.1)

SYMPTOMS
E-Business Suite 12.2 Applications DBA, Online Patching ADOP Utility issues
Running adop phase=prepare fails with following error:
[UNEXPECTED]Invalid worker Count: 0
[UNEXPECTED]Error while validating worker count
CAUSE
Error in database alert log showing maximum number of processes (200) exceeded during the adop execution.
The output from following sql can help to further verify and understand resource utilization:
select * from v$resource_limit where RESOURCE_NAME in ( 'processes' , 'cpu_count' , 'parallel_max_servers', 'sessions' ) ;
RESOURCE_NAME        CURRENT_UTILIZATION     MAX_UTILIZATION    INITIAL_ALLOCATION    LIMIT_VALUE
processes                  191                               200                       200                            200
sessions                    199                               243                       408                            408
parallel_max_servers    0                                  8                          8                               3600
parallel_min_servers     0                                  8                          8                                160
SOLUTION
To resolve the issue test the following steps in a development instance and then migrate accordingly:
1. Modify the init.ora file and increase the value of the following database initialization parameters per 'Note 396009.1 - Database Initialization Parameter Settings for Oracle Applications Release 12':
   A. processes
   B. sessions
   C. parallel_max_servers / parallel_min_servers
   D. open_cursors
2. Retest ADOP to confirm the required resources for the process to run successfully.
Note:
A convenient script is available for checking initialization parameters for E-Business Suite:
Note 174605.1 - bde_chk_cbo.sql - EBS initialization parameters - Healthcheck (Doc ID 174605.1)