To start Workflow components from back end.

SQL> select component_id,component_name, component_status FROM apps.fnd_svc_components WHERE component_type like '%WF%';

COMPONENT_ID COMPONENT_NAME                                                                   COMPONENT_STATUS

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

      10000 ECX Inbound Agent Listener                                                       STOPPED

      10001 ECX Transaction Agent Listener                                                   STOPPED

      10002 Workflow Deferred Agent Listener                                                 STOPPED

      10003 Workflow Deferred Notification Agent Listener                                    STOPPED

      10004 Workflow Error Agent Listener                                                    STOPPED

      10005 Workflow Inbound Notifications Agent Listener                                    STOPPED

      10006 Workflow Notification Mailer                                                     STOPPED

      10020 Workflow Java Deferred Agent Listener                                            STOPPED

      10021 Workflow Java Error Agent Listener                                               STOPPED

      10041 Workflow Inbound JMS Agent Listener                                              STOPPED

      10040 Web Services IN Agent                                                            STOPPED

      10042 Web Services OUT Agent                                                           STOPPED

      10043 WF_JMS_IN Listener(M4U)                                                          STOPPED

To start the WF components from back end:

SQL> declare

    retcode number(10);

    errbug varchar2(50);

    begin

    fnd_svc_component.start_component (10006,retcode,errbug);

    end;

    /

PL/SQL procedure successfully completed.