Alfresco workflow allows more than one workflow engine.
You can design workflow definitions using a graphical workflow designer that supports BPMN 2.0 or write the XML BPMN 2.0 process definition directly using an XML editor. Many workflow editors support BPMN 2.0 but might not understand some of the features of Alfresco workflow. We recommend the use of the Activiti eclipse designer plug‐in for Eclipse that is Alfresco-aware.
You can deploy a workflow to Alfresco using the Activiti Workflow Console, or by using a Spring Bean.
Alfresco allows you to access your own Java Classes through the delegate handler, so you can integrate with other external systems. The following diagram show these features :-