The Release by Integration Workflow is used to validate an Integration Assembly.
This workflow operated on the Integration CAD Structure only, meaning the Integration Assembly itself and all its CAD Dependencies if it has a valid lifecycle state (Approved, Released or Replaced). Once we identify the data we need to validate, we must prepare the workflow object (Change Item) and if all the pre-condition checks are passed, then launch the workflow. This sets the “Approved” lifecycle state on the Integration Assembly and automatically completes without any additional control activity. 

For more information, please follow the link below:

 Release For Integration Workflow