https://community.appian.com/discussions/f/general/8923/activity-chainingHi, Let us assume we have a Process Model having User Input Task along with Activity Chaining, now let us assume i want to call that process model from another process Model as Sub process, in that case we have 2 options, Synchronous and Asynchronousen-USTelligent Community 12https://community.appian.com/thread/39668?ContentTypeID=1Thu, 24 Nov 2016 22:01:34 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:7c664655-c1da-4d42-baf3-1a1dd4e329e2Rama Thummala@Alok <br />I think the reason for check box selected with disabled is , you have selected Synchronously and selected the activity chaining checkbox and then when select Asynchronous it is going to disabled mode.<div style="clear:both;"></div>https://community.appian.com/thread/39651?ContentTypeID=1Thu, 24 Nov 2016 10:07:14 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:4716d721-d66d-41e8-8960-a8e7bdbbcc2faloks0189Thanks<div style="clear:both;"></div>https://community.appian.com/thread/39649?ContentTypeID=1Thu, 24 Nov 2016 09:51:46 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:c9db77b4-428c-4277-b244-3a63d75dc0daKrishna ChaitanyaHi @alok<br />please go through the link below and it might help you..<br /><a href="https://forum.appian.com/suite/help/16.3/Activity-Chaining_into_a_Sub-Process_Activity.html">forum.appian.com/.../Activity-Chaining_into_a_Sub-Process_Activity.html</a><div style="clear:both;"></div>