https://community.appian.com/discussions/f/best-practices/21274/sub-process-vs-send-receive-message-eventA sub-process need to inform parent with details(CDT) , the parent process can call the child-process in asynchronous manner since parent process as some parallel activities. For this i have few approach : Parent will split the instances into twoen-USTelligent Community 12https://community.appian.com/thread/82943?ContentTypeID=1Thu, 24 Jun 2021 15:59:17 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:59f1d6a2-10ac-481a-a1db-6882fcd4b747aravind.s<p>thanks for your response Mike....</p> <p>The sub-process which we are referring can last upto 100hours(worst case ),which will do polling&nbsp;to external system(integration) for every 45 mins.&nbsp;</p> <p>Would&nbsp;you think this process-intensive?</p><div style="clear:both;"></div>https://community.appian.com/thread/82941?ContentTypeID=1Thu, 24 Jun 2021 15:15:28 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:418dc990-df6b-4f67-bb3d-bcac1cbc11eeMike Schmitt<p>Generally I&#39;d rather implement something closer to your first approach (split process flow with AND node, call subprocess synchronously, get data from it when done), because while the Send Message approach can work, it can be a nightmare in terms of management, debugging and upkeep.&nbsp; I don&#39;t expect either approach would be all that different in terms of performance unless the subprocess is doing something unusually process-intensive.</p><div style="clear:both;"></div>