Hi Ted Pan,
Thanks for your answer.
Guess you are right, we have to provide event or connection or any other method to re enter the task node and manually rollback our process.
there is a concern that by using process flow engine like jbpm our process become more rigid, but I guess we have to handle it.
here is a sample scenario, consider a self performance review system:
1. the employee need to make a self review and saves it on the system
2. the manager need to approve the review, If it is approved then the process ends, if it is rejected, then the employee needs to redo his task to edit / modify the self review.
Regards,
Thomas Setiabudi