Let's say we have a web application with a form, when we fill the form and click on submit button, it executes the BPMN workflow, then we want to give a success or error message to the user whether that particular action was succeeded or not. BPMN process: 1. Start event (Give required information) 2. Allocate Consultant (Save data in database) 3. Send email (Send email to relevant parties) 4. Change status (get human interaction to continue the process) 5. another task.... How this executes; When we start this process, it creates process instance, execute allocate consultant, send email and return response with process instance details, when it hits the user task. But that response does not contain any information about whether those executed tasks succeeded or not. Solution: Let's say when it executes allocate consultant task, it invokes database create operation; if it was failed, we want to give error message, else need to give success message. So, we