I'm trying to start the same Workflow on 10 different documents at the same time.  I thought this would be a perfect use of the Parallel Action.  I created a 10-branch action and in each I created For-Each loops.  And each loop is processing a different collection of Document IDs.  Review the Parallel Action attached file.  Each loop inside each branch is processing a different collection and each branch has its own set of variables.  Nothing is being shared between the branches. 

Each loop is calling the workflow.asmx service and using the StartWorkflowOnListItem web method.  See attached image for web service call.

What appears to be happening is each document's workflow is being started in series (one-at-a-time), instead of in parallel (all 10 at the same time).  And then due to the volume of documents it is trying to process, the WF times out and produces an Error Occurred.

I consciously removed the option in the WF to auto-start when the document is uploaded to the library because there were so many documents uploaded at the same time and all documents were trying to start the WF on itself and most of them would fail due to timeout.  That's why I came up with this design.

Without the parallel action, the WFs do start on all the documents....  eventually.  But it took a long time to start each one individually.  That is why I thought of the parallel action - hoping we could get some WFs to start at the same time.

Is there something wrong with my logic in calling this web service in each branch of the parallel action all at the same time?  Or have each parallel branch loop through a collection of Document IDs? 

Thanks in advance for any help or assistance.

Let me know if you need any more information

Nintex Workflow for SharePoint 2016 

Version 4.1.1.0