Hello Vicky,
Ideally BDoc messages with status I04 should not be created by any Business application. If the update task fails these BDoc messages are just dead bodies and have to be deleted manually – if the failed update tasks cannot be restarted (what happens normally) via SM13. If the update task can be restarted the I04 BDoc message would be processed.
What you can probably try is this:
To reprocess I04 outbound Bdocs use the report Z_PROCESS_BDOCS_I04(from note 835761). This report will pick up all the bdocs that are in status I04 and find the corresponding inbound bdocs. It will reprocess them as this requires the Inbound BDocs to be present as the re- processing has to happen starting from the inbound processing. This will update all the CRM database tables + will generate the outbound bdocs for updating the external systems to CRM, ex Mobile, BW, APO... So in short, The outbound mBDocs in the I04 status can be re-processed only if the corresponding inbound mBDocs can be located in the system.